iMac (Retina 5K, 27-inch, 2017) CPU and NVME SSD Upgrade Pitfalls and Tips

Discussion in 'iMac' started by rxs0, Apr 13, 2019.

  1. rxs0, Apr 13, 2019
    Last edited: Jun 17, 2019 at 1:57 AM

    rxs0 macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #1
    iMac (Retina 5K, 27-inch, 2017) CPU and NVMe SSD Upgrade Pitfalls and Tips

    UPDATE: Information regarding upgrading the 2019 27-inch IMac with the Intel i9-9900K CPU and 2TB Samsung 970 EVO NVMe SSD can be found in the post below:
    https://forums.macrumors.com/thread...itfalls-and-tips.2177812/page-3#post-27344487

    UPDATE: The Samsung 2TB 970 EVO Plus now works with macOS with new firmware update. See information below.


    I upgraded the CPU and SSD on my 2017 27-inch Retina 5K iMac, model A1419 (MNE92LL/A) to an i7-7700 processor and 2TB 970 EVO NVMe Samsung M.2 SSD as well as an 1TB 860 EVO SATA III SSD.

    Model Name: iMac
    Model Identifier: iMac18,3
    Processor Name: Intel Core i7-7700 4-cores, 8-threads, 3.6 GHz
    Processor Speed: 3.6 GHz
    Number of Processors: 1
    Total Number of Cores: 4
    L2 Cache (per Core): 256 KB
    L3 Cache: 8 MB
    Memory: 128 GB (4) Samsung 32GB DDR4 2666MHz Sodimm (M471A4G43MB1-CTD)
    Graphics: AMD Radeon Pro 570 4 GB

    Device: Mid 2017 - 18.3 - MNE92LL/A (3.6Ghz i7-7700, Fusion HDD+32GB blade)
    Blade upgrade: 32GB Blade -> 2TB Samsung 970 EVO NVMe SSD
    HDD upgrade: 1TB SATA HDD -> 1TB Samsung 960 EVO SATA SSD
    Speed test: blade 2500 MB/s write, 3000 MB/s read, SATA SSD 450-ish
    OS: Mojave 10.14.5
    Adapter: Sintech ST-NGFF2013-C with additional Kapton tape, OWC temperature sensor not used
    Issues after fresh OS install and restore: NONE, No sleep or hibernate issues
    Boot ROM Version: 172.0.0.0.0
    SMC Version (system): 2.41f1

    Although upgrading the iMac is straightforward and relatively easy, there are (3) main potential installation problems which can lead to an inoperable and damaged iMac.

    1. Screen falling off after reassembly, usually due to incorrect display adhesive strip application or use of cheap non-OEM after-market adhesive strips which can fail several days to months after iMac screen reassembly.

    2. Incorrect installation of CPU with the overly high tension CPU mounting spring, resulting in bending of the CPU wafer board and possibly damage to the logic board socket pins.

    3. Faulty installation of the non-Apple NVME M.2 drive using the Sintech adapter, which can result in electrical shorting between the adapter's electrical "wiring" and the metal shield of the logic board NVME connector. In my case, this problem developed several days after a "successful" install.

    I also added mistakes from other users experience resulting in damage to their iMacs during the upgrade process, the most costly of which include the screen, logic board, and CPU. It is my hope that this “guide” will help you succeed with your upgrade and prevent major damage to your computer. I will post pertinent pictures into this post below. Please feel free to add your upgrade pitfalls, tips, and advise to this post. Good luck.


    Tools/Parts:
    1. I used a long strip of painters tape, sticky side up, folded at each end to the table, to attach and spatially organize the screws during disassembly process. You can also label the tape with a pen by component, such as left speaker, hard drive assembly, power supply, cooler, logic board, wifi, and right speaker. This organization facilitates quick reassembly. Alternatively, you could use the magnetic project mat by ifixit, as seen in the first repair video below.
    https://www.ifixit.com/Store/Tools/Magnetic-Project-Mat/IF145-167?o=4
    https://www.amazon.com/Magnetic-Pro...ACECT32M1RK&psc=1&refRID=04YK8W894ACECT32M1RK
    2. Toolkits:

    iFixit Manta Driver Kit - High quality toolkit which includes a wide assortment of 112 steel bits, highly recommended
    https://www.ifixit.com/Store/Tools/Manta-Driver-Kit--112-Bit-Driver-Kit/IF145-392
    https://www.amazon.com/iFixit-Manta-Driver-Kit-Piece/dp/B07BMM74FD/ref=sr_1_1_sspa?crid=ECSB62CHVP1O&keywords=manta+driver+kit&qid=1557054516&s=hi&sprefix=manta+,tools,160&sr=1-1-catcorr-spons&psc=1

    iFixit Pro Tech Toolkit
    https://www.ifixit.com/Store/Tools/Pro-Tech-Toolkit/IF145-307

    LB1 High Performance Electronics Precision Repair Tool Kit (54 Piece Kit) - Top notch toolkit. This kit includes the T20, T10, T8, and T5 tips needed for servicing. T25 bit not included in this kit. The included T20 bit however works just fine with the T25 standoffs discussed below.
    https://www.amazon.com/gp/product/B01DAWZ3ZG/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

    3. Odyson - Two-in-One Service Wedge Repair Tool Replacement for iMac 21.5" & 27" (Late 2009-Mid 2017) - This wedge perfectly stabilizes and slants the computer case back to make for easy repairs. Highly recommended. You can also use a small pillow.
    https://www.amazon.com/gp/product/B0781GF4MR/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

    4. OWC in-Line Digital Thermal Sensor HDD Upgrade Cable and Install Tools for iMac 2012, (OWCDIYIMACHDD12)
    https://www.amazon.com/gp/product/B00J42HP9O/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

    This kit includes:
    • (1) OWC In-line Digital Thermal Sensor Cable
    • (1) Cutting wheel to cut display adhesive
    • (2) OWC 2-1/4" Suction Cup
    • (1) Torx T10S Driver
    • (1) Torx T8S Driver
    • (1) Nylon Pry Tool (Spudger)
    • (1) Set of Adhesive strips
    • (1) OWC Blue Microfiber Screen Cleaning Cloth
    These tools and parts can also be purchased individually:
    https://www.amazon.com/Opening-Hand...ing+wheel&qid=1556435379&s=electronics&sr=1-2

    This In-Line Digital Thermal Sensor HDD Upgrade Cable device is presumably necessary to prevent cooler fan from going continuously full blast. I however did not need this device and suffered no problems with the fan going continuously full blast without the device. Again, I experienced no problems without the OWC device, with removal of both fusion SSD and hard drive components.

    I personally would avoid this use of these adhesive strips as there have been multiple reports of screens falling off after reassembly, a very costly problem. Read the multiple negative Amazon reviews of this product regarding adhesive strips failing, with screens falling off and breaking.
    https://www.amazon.com/OWC-Digital-...e=all_reviews&pageNumber=1#reviews-filter-bar


    5. Painter’s tape for securing bottom edge of screen during testing and reassembly. See post #3 pictures.
    https://www.amazon.com/ScotchBlue-P...e&qid=1557760855&s=gateway&sr=8-1-spons&psc=1
    6. Spudger - Highly useful tool to help pry off very small connectors. Don’t pull on cable to remove connector as this may damage cable and/or connector.
    DO NOT USE THE GREEN OR BLACK SPUDGER DEVICES TO PRY OFF SCREEN! This will result in cracking of the very thin delicate display glass!
    https://www.ifixit.com/Store/Tools/Spudger/IF145-002?o=2
    https://www.ifixit.com/Store/Tools/Spudger-Retail-3-Pack/IF145-334?o=1
    7. NewerTech AdaptaDrive 2.5" to 3.5" Drive Converter Bracket - One of the best brackets to mount 2.5” SSD SATA drive in existing hard drive assembly. Very well made.
    https://www.amazon.com/gp/product/B005PZDVF6/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
    8. NVME Adapter Update:

    Don't use this short adapter (ST-NGFF2013).
    https://www.amazon.com/gp/product/B07FYY3H5F/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1 Sintech NGFF M.2 nVME SSD Adapter Card for Upgrade MacBook Air(2013-2016 Year) and Mac PRO(Late 2013-2015 Year)

    Instead, use this long black adapter version (ST-NGFF2013C), with additional Kapton tape
    https://www.amazon.com/gp/product/B01CWWAENG/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
    http://eshop.sintech.cn/ngff-m2-pcie-ssd-card-as-2013-2014-2015-macbook-ssd-p-1229.html
    Sintech NGFF M.2 nVME SSD Adapter Card for Upgrade 2013-2015 Year Macs(Not Fit Early 2013 MacBook Pro)

    This is the adapter used to convert conventional the M.2 NVMe connector to Apple proprietary connector. Be sure your adapter has insulation tape at the Apple end of the adapter to prevent electrical shorting with metallic shroud on logic board M.2 SSD connector.

    Update: I ended using the long black adapter version of the Sintech adapter (ST-NGFF2013C).

    I was only able to get a slower Link Width x2 speed with the short adapter, ST-NGFF2013, and successfully achieved a faster Link Width x 4 speed with the longer adapter, ST-NGFF2013C.

    The longer adapter likely promotes better alignment of the contacts. The shorter adapter/NVME combo fits tightly on logic board and demonstrated peeling back of the adapter's insulating tape. This may result in suboptimal alignment and possible shorting of connector contacts, and thus slower negotiated speed. See posts #28 and 33.

    9. Thin Card to help pry adhesive tape holding screen in place. I just used the cutting wheel.
    https://www.ifixit.com/Store/Tools/Plastic-Cards/IF145-101?o=1
    10. Microfiber cloth - multiple uses
    https://www.amazon.com/MagicFiber-M...d=1557660942&s=electronics&sr=1-1-spons&psc=1
    11. Thermal Paste - Arctic Silver 5 or Arctic MX-4.
    https://www.amazon.com/gp/product/B00LT0ZWJE/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1
    https://www.amazon.com/gp/product/B0795DP124/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1
    12. EKWB EK-M.2 NVMe Heatsink- Black
    https://www.amazon.com/gp/product/B073RHHYCM/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
    13. Vanilla 2-inch no residue masking/painter's tape for multiple uses as discussed below.
    https://www.amazon.com/No-Residue-E...&qid=1555694020&s=gateway&sr=8-33-spons&psc=1
    14. Samsung 970 EVO 2TB - NVMe PCIe M.2 2280 SSD (MZ-V7E2T0BW), Black/Red
    https://www.amazon.com/gp/product/B07C8Y31G1/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

    The 970 EVO drive is based on M.2 2280 design, that is, it measures 22 mm wide and 80 mm long and uses x4 PCIe Gen 3 to connect to the host computer.
    No current upgradeable firmware via Magician Software since Apr 2018

    ***Update May 26, 2019***
    Previously the Samsung 970 EVO Plus (with old firmware) did NOT work reliably with macOS.
    Samsung has recently released a firmware update for the Samsung 970 EVO Plus on May 26, 2019 which fixes issues with macOS.
    This will now likely be the fastest 2TB NVMe drive available for macOS.

    https://www.reddit.com/r/hackintosh/comments/bsj0w0/psa_samsung_released_a_firmware_update_for_the/
    https://www.ifixit.com/Answers/View/411888/NVME+M.2+SSD+with+adapter#answer572940

    "I am getting roughly 3k read and write speeds, so if the performance is indeed worse than before, it's not by much. I can now also confirm that the 970 EVO Plus does seem to work well with 10.14.5 and the firmware update. Many hours later and hundreds of gigabytes transferred and I have no issues with the Plus."
    sanmyaku
    https://www.samsung.com/semiconductor/minisite/ssd/product/consumer/970evoplus/
    https://s3.ap-northeast-2.amazonaws...A78151C/Samsung_SSD_970_EVO_Plus_2B2QEXM7.iso
    https://bartechtv.com/samsung-relea...lus-that-resolves-macos-compatibility-issues/
    https://forums.macrumors.com/threads/blade-ssds-nvme-ahci.2146725/page-35#post-27385884

    Update from Zach on iFixit.com: Zach had trouble with the following NVMe drives on his new 2019 27-inch iMac:
    https://www.ifixit.com/Answers/View...ades:+2019+vs+2017+27-inch+iMacs#answer568985
    - 1TB WD Black drive
    - 1TB 970 EVO Pro drive


    15. Apple proprietary NVME drives.
    https://beetstech.com/product/sspolaris-ssd-256gb-512gb-1tb-2tb
    16. Samsung 860 EVO 1TB 2.5 Inch SATA III Internal SSD (MZ-76E1T0B/AM)
    https://www.amazon.com/Samsung-Inch...+sata+ssd+860&qid=1555837192&s=gateway&sr=8-3
    17. Intel Core i7-7700 Desktop Processor 4 Cores up to 4.2 GHz LGA 1151 100/200 Series 65W
    https://www.amazon.com/gp/product/B01N0L41N7/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
    18. NEW Apple 076-00332 LCD Adhesive Strips, iMac 27” 2017 Retina 5K A1419 VHB (Very High Bond) Adhesive Strips
    https://www.ebay.com/itm/NEW-Apple-...ugAAOSwdilcn4so:sc:USPSFirstClass!46060!US!-1
    https://www.ebay.com/itm/x20-NEW-Apple-076-00332-LCD-Adhesive-Strips-iMac-27-2017-Retina-5K-A1419/332439434940?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
    https://www.ifixit.com/Store/Tools/3M-Double-Sided-Adhesive-Tape--2-mm-Width/IF145-283?o=1
    19. I will be testing this 3M 94 Tape Primer.
    https://www.ifixit.com/Store/Tools/Primer-94/IF317-076?o=1
    https://www.amazon.com/3M-Primer-3-...GKBV8VMN9KM&psc=1&refRID=M5S70STH2GKBV8VMN9KM
    https://www.amazon.com/New-Hi-Transparent-Adhesion-Promoter-Adhesive/dp/B07D8FFX19
    20. Magnetic telescoping screw pickup tool.
    The Manta Drive Kit listed above includes a magnetic pick up bit.
    Slim 25” Durable Telescoping Magnetic Grabber/Retrieving Magnet with Pocket Clip (07228)
    https://www.amazon.com/Master-Magne...3Q0FAGPVR65&psc=1&refRID=3G7H38BJG3Q0FAGPVR65
    https://www.ifixit.com/Store/Tools/Magnetic-Pickup-Tool/IF145-078?o=2
    21. NVME screw - I ended up using one of the included screws (M2 6mm) which came with the Sabrent NVME drive enclosure, which fit perfectly. The stock Apple screw did not fit as well. See post #25.
    22. Consider Anti-Static ESD mat and wrist strap to prevent damage related to static electricity.
    https://www.ifixit.com/Store/Tools/Anti-Static-Mat/IF145-036?o=1
    https://www.ifixit.com/Store/Tools/Anti-Static-Wrist-Strap/IF145-071?o=1
    23. Kapton Tape - Polyimide High Temperature Resistant Tape
    https://www.amazon.com/gp/product/B072Z92QZ2/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1
    https://www.macpartsdepot.com/922-1731-macs-kapton-tape-0-5-inch-by-36-yards.html
    https://en.wikipedia.org/wiki/Kapton
    24. Heat gun - used to heat adhesive strips during display reassembly for "better" bond
    https://www.ifixit.com/Store/Tools/Heat-Gun/IF145-031?o=1
    https://www.amazon.com/gp/product/B07NG78Q31/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
    The heat gun is used by some repair shops. Probably not recommended since excess heat could damage screen electronics.
    25. 923-01322 Antenna tool - (not necessary, but helps) https://www.ebay.com/itm/2PK-Antenn...-Pro-13-Part-923-01322-92301322-/113667617401
    26. ESD-safe tweezers - https://www.amazon.com/Kingsdun-Pre...safe+tweezers&qid=1557583611&s=gateway&sr=8-4
    27. Tech Spray Wipes Isopropyl Alcohol 99% Pure 50/Pack
    https://www.amazon.com/Tech-Spray-W...echspray+1610&qid=1557586849&s=gateway&sr=8-4
    28. Silicone Display Roller - 922-8261
    Alternatively, you can apply pressure with a microfiber cloth to the areas with adhesive strips.
    https://www.amazon.com/Aexit-Manual...ler+silicone&qid=1557653892&s=gateway&sr=8-65
    Be sure to cover aluminum frame with tape to prevent scratching of glass screen.
    29. Apple Nylon Probe/Spudger Tool (Black Stick) 922-5065
    https://www.amazon.com/Apple-Nylon-...ords=922-5065&qid=1557656077&s=gateway&sr=8-5
    30. Display extension cable set (076-00010) for iMac (Retina 5K, 27-inch, Late 2014–2017)
    https://www.ebay.com/itm/NEW-076-00...e-Set-for-iMacRetina-5K-27-2017-/173130361968
    Not necessary, allows you to:
    - test the system and/or panel before securing the panel to the very high bond (VHB) adhesive strips.
    - test the functionality of the panel’s Embedded DisplayPort (eDP) cable.


    Apple Flash Storage:
    661-07311, 32GB
    661-07312, 128GB
    661-07315, 256GB
    661-07317, 512GB
    661-07319, 1TB
    661-07320, 2TB


    Repair/Teardown Guides and Upgrade YouTube Videos:
    1. Excellent video showing all steps.
    2. https://www.ifixit.com/Guide/iMac+Intel+27-Inch+Retina+5K+Display+CPU+Replacement/30515 ifixit guide showing disassembly. The 2015 27-inch iMac guide is virtually identical to the 2017 27-inch iMac except for the addition of a new tiny ribbon microphone cable at the bottom right of the logic board and a new mounting system for the WIFI cables.
    3. .
    4. How to apply adhesive strips
    5. .
    6. -
    7. -
    8. .
    9. https://www.youtube.com/watch?v=knMM9dRwIH4&t=57s.
    10. https://www.youtube.com/watch?v=x5N3IELMdjI.
    11. https://www.youtube.com/watch?v=xZv-Q8-fZZI.
    12. https://www.youtube.com/watch?v=HZIiF4fczYA.
    13. https://www.youtube.com/watch?v=FFSyfT31AHI.
    14. https://www.youtube.com/watch?v=JYXURhQrueU The 2017 27-inch model now uses T8 screws for the power supply, logic board, and NVME drive. They forgot to plug in some usb cables into the back side of the iMac to ensure proper port alignment prior to logic board reassembly. WIFI connector cables are now secured in the 2017 model by metal tabs, held by (2) T5 screws.
    15. https://www.youtube.com/watch?time_continue=32&v=Fl_4kW76ElI
    16. https://www.youtube.com/watch?time_continue=1053&v=faqUAJpbWUA
    17. Thermal Cooling pads, for use on VRMs.
    https://www.ebay.com/i/173872862487?chn=ps&var=472593568183
    http://vi.raptor.ebaydesc.com/ws/eB...171&category=181907&pm=1&ds=0&t=1556169129434
    https://es.aliexpress.com/item/Alta...241.html?spm=a2g0s.9042311.0.0.3c7063c00W75L3
    18. https://www.youtube.com/watch?v=gTWNQIOwAUQ
    19. https://www.youtube.com/watch?v=pS6rqRkyN-s


    iMac Upgrade FAQs: https://everymac.com/systems/apple/...grade-imac-hard-drive-aluminum-2012-2013.html


    Screws:
    - T25: Metal Spacers/Standoffs (I ended up using an available T20 bit which worked just fine)
    - T10: Speakers, CPU Mounting Spring, Cooler Fan, (2) upper Heatsink screws
    - T8: Hard Drive brackets, Pins on Hard Drive, Power Supply, Logic Board, GPU bracket, SSD NVME
    - T5: WIFI
    - PH00: Small Phillips screws holding bottom "trim". I didn't remove the trim. You can just loosen and push speakers out of the way without removing the speakers from the chassis.


    MacOS Operating System Installation on New Drives and Recommended Supportive Hardware:
    1. Cloning software: https://bombich.com - Carbon Copy Cloner - time proven cloning software
    2. https://eshop.macsales.com/guides/Cloning-Your-Data-to-a-New-Hard-Drive
    I used the simpler Carbon Copy Cloner method to clone my drive.
    3. https://www.youtube.com/watch?v=pxmGV2WH3Jo&t=24s
    4. Sabrent USB 3.1 Aluminum Enclosure for M.2 NVMe SSD in Gray (EC-NVME) - I used this excellent very fast enclosure to copy my drive image to the NVME drive.
    https://www.amazon.com/Sabrent-Alum...+3.1&qid=1555094958&s=gateway&sr=8-3-fkmrnull
    5. Sabrent USB 3.1 (Type-A) to SSD / 2.5-Inch SATA Hard Drive Adapter
    After initializing, erasing/reformating the drive to APFS filesystem and GUID map/table, and renaming the drive to Macintosh HD with the Disk Utility, I used this drive to copy the boot drive to this SATA SSD drive. I have it setup so that I can boot from either the NVME or SSD SATA drive after pressing the “option” key during restart of the computer.
    https://www.amazon.com/Sabrent-2-5-...+3.1+sabrent&qid=1555095227&s=gateway&sr=8-16

    6. How to reinstall macOS from macOS Recovery (using network to download macOS installer)
    If you are installing a fresh Mojave install and don't want to use a separate bootable USB drive for the new macOS installation, you can also install macOS from macOS Recovery to the latest macOS using a network connection after booting using the:

    Option-⌘-R (Upgrade to the latest macOS compatible with your Mac) key combination.

    First use Disk Utility to erase and format your disk to:
    Name: Macintosh HD
    Format: APFS
    Scheme: GUID Partition Map
    https://support.apple.com/en-us/HT208496

    Then:
    Choose Reinstall macOS (or Reinstall OS X) from the Utilities window.
    Click Continue, then follow the onscreen instructions to choose your disk and begin installation.

    https://support.apple.com/en-us/HT204904

    7. How to create a bootable installer for macOS
    https://support.apple.com/en-us/HT201372
    8. Consider disabling SIP (System Integrity Protect) on the bootable drive. Command: csrutil disable
    9. Be sure to backup all you data.
    10. Trim is automatically enabled for NVMe drives by default.
    Trim is enabled with the following command (not necessary with NVMe drive, again enabled automatically):
    sudo trimforce enable
    http://osxdaily.com/2015/10/29/use-trimforce-trim-ssd-mac-os-x/
    Trim Enabler software - You may need this to enable Trim on a SATA SSD drive.
    https://cindori.org/trimenabler/
    11. Mac startup key combinations
    https://support.apple.com/en-us/HT201255
    12. You will need to update your iMac to Sierra (10.13+) or Mojave to install the latest iMac firmware update that will allow the NVMe drive to be supported.
    Consider updating to Sierra or Mojave before performing the hardware upgrade.
    My current firmware version:
    Boot ROM Version: 172.0.0.0.0
    SMC Version (system): 2.41f1


    Screen Removal and Reassembly with Adhesive Strips:
    1. Before starting repair:
    • Turn off the computer.
    • Unplug the power cord from the electrical outlet.
    • Disconnect all cables.
    • Put on an ESD wrist strap and attach it to a properly grounded ESD mat.
    Don’t try to use a suction method on the newer thin iMacs as it will almost always result in a cracked display. This only works on the older displays held in place by magnets.

    Consider removing the screen while laying the computer down on a table as several users have accidentally dropped the screen on the table when removing screen in the upright position. This happened to Linus on YouTube after his tech was startled when the back of the screen made contact with the power supply causing a spark, resulting in dropping the screen. Expensive mistake. https://www.youtube.com/watch?v=9-NU7yOSElE

    2. Insert the display removal tool at a 90-degree angle (hold the display removal tool perpendicular to the edge of the computer) in the top left corner between the display and rear housing. Roll the tool across the top of the computer, avoiding the 3-inch area surrounding the camera. The tool should only be used along the top and sides of the display, not along the chin.

    Be sure to use the cutting wheel to cut the adhesive tape holding the display in place in a straight line, with back and forth cutting. Do not torque or try to pry screen off with tool as you can crack the glass. Use your hands to gently pry the display off after the adhesive strips have been cut. Do not use the green or black spudgers to pry off screen as this can result in cracking your glass display. Avoid pulling too hard on suction cups as there is at least one YouTuber who bent his display with too much force. I did not use the suction cups. I just used the cutting wheel and my fingers to gently pry open the display.

    3. Use a service wedge to secure computer in place to fix computer in a slanted back position.
    4. Use Apple OEM adhesive to reapply screen. There are multiple forum posts and Amazon reviews of failed adhesive strips and videos discussing use of incorrectly applied or cheap after market adhesive tapes failing. This can result in screen coming loose and falling onto table, resulting in possible damage to the screen, display cables, and logic board.
    https://www.youtube.com/watch?v=Sntb7FyFlnw&t=61s
    https://forums.macrumors.com/threads/worlds-saddest-mac-story-or-how-i-royally-screwed-things-up.2179105/
    https://www.amazon.com/OWC-Digital-...e=all_reviews&pageNumber=1#reviews-filter-bar

    5. After removal of screen during disassembly, completely remove all residual strips and clean off residual sticky adhesive with greater than 90% isopropyl alcohol (IPA) and lint-free cloth.

    Do not peel VHB from the display corners. The chance of damaging the black Mylar protective film is greater if VHB removal is started in the corner.

    Wipe IPA wipes in one direction, not back and forth. The surface needs to be clean and dry prior to adhesive tape reapplication.

    Use an IPA (isopropyl alcohol) wipe (at the end of a flat spudger tool) to remove any remaining adhesive from the rear housing and display edges. Allow the surfaces to dry for 1 minute.

    https://www.ifixit.com/Answers/View...r+Repair+-+New+Adhesive+Not+Sticking+Properly
    https://www.youtube.com/watch?v=6NZ385-XNdA&t=201s

    6. Consider adding small velcro pads to the front of speakers - back of display as a secondary protection in case the adhesive strips fail.
    7. Add a strip of tape to the lower edge of the screen during disassembly to prevent accidental slippage of the screen during removal. I used gorilla clear double sided tape which leaves no residue and ensures a very strong bond. I also used multiple small pieces of the tape on the outside of the screen to keep the iMac display in place for testing, prior to final sealing with adhesive strips.
    8. Consider applying prolonged compression to the screen after the application of adhesive strips to ensure a good bond. You can use some plastic clamps on top of thin books with gently pressure or lay computer down and place some books on the screen to apply some gentle downward pressure.
    9. When prying off screen, avoid stretching the screen power and data cables. The screen data cable has a wire locking latch that needs to be flipped back prior to unseating cable. Gently pry the screen power cable with a spudger tool at the connector. Avoid pulling back on cable as this may damage cable and/or connector.
    10. Be sure to use OEM adhesive strips to ensure easy future removal of screen. These strips contain foam which allows for easy cutting. Use of nonstandard non-foam strips with excessive adhesion can lead to great difficultly removing screen and possibly a cracked screen if you are forced to use excessive prying force. I’d rather have temporary pieces of tape holding the outside of the display in place for a few weeks to confirm successful adhesive tape application. There are reports of the adhesive strips failing up to six months after reapplication! https://forums.macrumors.com/threads/broken-screen-27”-pics.2128286/#post-26266424
    11. Keep your work surface free of any tools such as screw drivers as you remove your screen as you can crack the fragile screen by resting it on a screw driver.
    12. Screen Replacements:
    http://www.ifixmaccomputers.com/imac-27-inch-5k-mid-2017-lcd-panel-assembly-replacement-apple-661-07323?search=iMac 27-inch 5K, Mid-2017
    https://www.amazon.com/gp/product/B...SQ633&linkId=6fe4a39e58ca5fc125432d1778f57a36
    13. Use painter's tape or masking tape to temporarily secure the bottom edge of the display to the iMac's enclosure. The tape preserves the display's alignment, and allows you to safely swing the top edge of the display open to access the display cables.
    14. When reattaching display with adhesives, ensure the display is along the bottom edge of the chassis as flush with the lip, as centered as possible, avoiding any gap. Don't let the display close yet as you need to reconnect the video cables. Before lowering the screen in place, you want to first plug in and power up iMac to make sure that it boots without issue. After checking, power down the system before making any adjustments or completing the installation. You can now carefully lower the display into place, making sure you have the edges lined up correctly. Then gently squeeze along the edges to make sure the adhesive sticks. Use the microfiber cloth to remove any finger prints or suction marks.
    15. https://www.ifixit.com/Guide/iMac+Intel+27-Inch+EMC+2546+Adhesive+Strips+Replacement/15624
    16. Consider use of multiple A-clamps to clamp around the edge of the screen, overnight, to ensure good adhesive bonding. https://www.mac-forums.com/forums/apple-desktops/346491-imac-screen-fell.html
    17. https://ifixit-guide-pdfs.s3.amazonaws.com/pdf/ifixit/guide_24341_en.pdf
    18. Given the potential of delay problems that can make your iMac unstable or inoperable (such as the NVME/adapter assembly), consider delaying application of the adhesive strips after the computer has been stable and up and running for at least a week. In the meantime, you can apply strong adhesive non-residue tape to keep the display in place.
    19. Be sure to check that you have reconnected all of the internal cables prior to re-applying the display.
    20. Use the silicone display roller to adhere the display adhesive strips (on the sides of the display) to the glass. To prevent image quality issues, only roll upward. Roll the silicone display roller along the top in a horizontal back-and-forth motion.
    21. Lay out the adhesive strips and inspect them for damage, wrinkles, or exposed sections. Damage can cause cosmetic gaps and leakage and weaken the bond.
    22. If a display adhesive strip does not line up correctly, remove it, clean the rear housing, and start again. Ensure there are no wrinkles or exposed sections on the strip.
    23. Be careful when removing VHB from the display panel. To prevent damage to the black Mylar protective film that is located on the display panel glass, ensure that you are peeling up the VHB and not the Mylar film. An easy way to ensure that you do not peel up the Mylar film on the display is to start peeling the VHB from the center points, not from the corners of the display.
    24. During screen reassembly, the bottom right adhesive strip labeled 25 for iMac (2017) has a perforation in the VHB for the microphone hole, refer to image below (see post below). Make sure to use the correct strip and line up the perforation with the microphone hole or it could lead to microphone issues [that is, poor muffled recording sound quality].


    Disconnecting Logic Board Cables/Cable Management:
    1. Do not pull on the tab on the tiny thin ribbon cable (microphone cable) at the bottom right of the logic board. The tab will avulse/rip off. Mine did. :( Use your spudger tool to gently pry and slip off connector. Take your time. Again, do not pull back on cable or tab. The tab is only used to position the cable back into it’s connector during reassembly.
    2. Tape down microphone ribbon cable to front of case to keep cable out of the way, during logic board reassembly.
    3. The power supply connectors on the back of the power supply board both have locking latches that need to be depressed in order to remove the connector.
    4. Consider using tape to label the order of WIFI connectors. You can also take a picture with your cell phone to note the correct order. The picture provided in posts below show the correct order of cables.
    5. Again, remember to detach the metallic wire latches (known as "Locking Lever Bails") that secure the Display Data Cable and iSight Camera Cable.


    CPU and Heatsink Reassembly:
    1. Forum posts and YouTube videos documenting the bent CPU problem.
    - https://www.youtube.com/watch?v=knMM9dRwIH4&t=57s Footnote #3: A little drama that wasn't included in the video is that the first time around, the CPU got bumped out of the socket when I screwed in the cooler, so the CPU wasn't seated correctly and the computer didn't boot. Upon disassembling the machine again, I saw the CPU was out of the socket and partially bent. I bent the CPU back (silicon bends easily without damaging, luckily), reinserted it into the socket, and was more careful when I tightened the CPU cooler the second time. It's easy to wiggle the CPU out of place when installing the cooler, so be careful—and if it feels too hard to tighten the CPU socket, stop—something is wrong.
    - https://www.youtube.com/watch?v=Du89MIXny7k bent cpu mistake discussed at 3:57 in the video
    - #23
    - https://forums.macrumors.com/thread...017-ssd-upgrades.2162435/page-2#post-27115420
    - Multiple users, including myself, have fallen into the trap of incorrectly reassembling the CPU spring (single "Leaf Spring") and heatsink to the logic board. I was aware of this problem and still screwed it up. :( In my opinion, the CPU spring tension is very excessive. Ideally, two people could perform the installation as in one of the videos. Note that (2) of the screws on the same side of the spring are secured first, followed by pressing down spring and securing the 3rd and 4th screws. Others have installed the screws diagonally. Given the high tension of the spring, it is too easy to misalign the CPU in the reassembly process. Also, you will likely literally bend your CPU if you screw the screws all the way down. You should probably only screw the screws partially, no more than half-way down. My solution was to remove some of the excessive tension by removing some of the extreme bend by bending/partially straightening the spring in a wood vise/clamp. This resulted in less spring tension and more optimal alignment of the screw holes of the spring so that the screws could be easily anchored by hand prior to final tightening. You can always re-bend the spring back if necessary. I still had more than enough spring tension after the spring modification. I have had no CPU problems.
    2. If you are gun shy about bending your CPU Spring, you can order a used backup spring on Ebay. Look up iMac Heatsinks on Ebay.
    3. Place some painter’s tape on the GPU mounting bracket on the backside of the logic board to keep the GPU bracket held in place and aligned with the screw holes after removal of screws. This can save you a little time with realignment when reassembling the CPU/GPU.
    4. Avoid too much thermal paste.
    5. One person’s advise: Do not over-tighten the CPU. If you look under the board, you don’t want to see the base of the screw coming through the hole or you are going too tight.
    6. Diagnostic LEDs: "If you only have one green led [LED 1], search for some mistake, any bad connection, power supply not connected or the CPU not seated correctly in the socket. My problem was the CPU was incorrectly seated."
    7. Securing GPU bracket first during heatsink reassembly will help to align and minimize movement of the heatsink assembly during CPU spring tightening.


    Speakers:
    1. Consider removing the bottom trim (Apple calls this the "Chin Strap") held by Phillips screws to aid in speaker removal. https://www.youtube.com/watch?v=YSgcJH5bdWM. This isn’t necessary, but makes it easier to remove speakers. I left my in place with no problem. You just have to apply a little more effort.
    2. When removing left speaker, be sure to remove recessed cable for "power button" prior to complete removal of left speaker as you can easily rip out cable.
    3. Be sure to fit “power button” cable into the recessed groove of the left speaker prior to reassembly of left speaker into case.
    4. Regarding right speaker reassembly, connect the right speaker connector prior to final alignment and mounting of right speaker.
    5. Avoid touching small speaker domes and tiny tweeters during disassembly and reassembly as they can be easily damaged.


    Hard Drive Assembly:
    1. The right hard drive bracket lower screw does not have to be removed. This allows you to flip bracket out of the way.
    2. The SATA cable runs above cpu heatsink exhaust duct and under the right hard drive bracket.
    3. The hard drive assembly has to be reinstalled before the left speaker.
    4. The right hard drive bracket lower screw/spacer has to be installed before logic board.
    5. Don't forget to remove the (4) T8 mounting hard drive pins/pegs from the 3.5" spinning hard drive, which slide into the rubber grommets of the hard drive brackets.


    Cooler Assembly:
    1. Consider blowing dust out of cooler assembly.
    2. Don’t forget to pull the heatsink duct adhesive flap (black Mylar shield) in front of and on top of cooler and reapply adhesive flap to cooler to maintain a good seal.


    Power Supply (300W):
    1. Avoid touching contacts.
    2. Depress connector latches/tabs on back of power supply to remove connectors as above.
    3. http://www.ifixmaccomputers.com/661-03524-apple-power-supply-imac-27inch-late-2015-a1419?search=iMac 27-inch 5K, Mid-2017
    4. The spacer with the shorter screw stem is used to bolt down the left black flange of the heatsink duct/logic board. The top right power supply screw then screws into this spacer.
    5. Consider applying a taped temporary sheet of "insulating" paper to the back of the power supply during disassembly/reassembly to prevent accidental electrical shorting with the metallic back surface of the display. This shouldn't happen if the bottom edge of the display is securely resting on the bottom of the iMac case ledge. This is however how Linus's tech broke their screen as mentioned above.
    6. When reassembling power supply, first connect the AC inlet cable along the bottom right of the front of the power supply.
    7. The AC inlet cable should rest below the adjacent bottom right spacer/standoff.
    8. I inserted a partially folder envelope between the power supply board and the case to prevent accidental shorting during removal and installation of the power supply.
    9. The (2) long T8 screws mount the top of the power supply. The (2) short T8 screws mount the bottom of the power supply.
    10. https://beetstech.com/product/power-supply-300w-661-7886


    Logic Board:
    1. When reassembling the logic board, first secure logic board with central captive screw (located inside the hole) partially tightened. The tool kit screw-driver listed above fits perfectly into this hole. This captive screw corresponds to the screw along the black right heatsink duct tab. Then plug in test USB, thunderbolt, and network cables to properly align the logic board ports with corresponding cutouts in the case housing, and then apply and tighten logic board screws. One guy had to take apart his iMac again since the ports did not line up the the case slots after reassembly. This is clearly showed in the videos/guides above.
    2. Consider use of 1mm thermal pads for the VRMs as in this video instead of thermal paste. https://www.youtube.com/watch?v=HZIiF4fczYA. I just used Arctic Silver 5 paste.
    3. Be sure to note how the long spacer/standoff (with short stem screw) anchors the left black tab off the Heatsink assembly. The upper right screw of the power supply then screws into this standoff.
    4. The spacer with the longer screw stem bolts down the bottom hole of the right hard drive bracket. This spacer can be loosened but left in place during disassembly. The leftmost logic board screw then screws into this spacer.
    5. Use the flat portion of the spudger to gently pry off the WIFI connectors. See picture below.
    6. http://www.ifixmaccomputers.com/ima...-2ghz-logic-board-replacement-apple-661-03383
    7. For the (2) T8 screws on the top of the heatsink duct, consider using the "flexible screw driver" since the screws are difficult to engage given the limited space.
    8. Caution: Do not lift the flash storage card at an angle when removing it from the connector. If you damage the connector, you must replace the logic board.
    9. Pay special attention to the areas in the images below when handling the logic board. Mishandling the logic board can damage chips and circuits. Components that accidentally touch the rear housing may damage the computer and keep it from operating correctly.


    NVME drive/Heatsink/Sintech Long Black Adapter Assembly
    I HIGHLY recommend you use Kapton tape to insulate the Sintech long black NVME adapter.
    Please see post #33


    Disk Benchmark Software:
    1. AJA System Test https://www.aja.com/products/aja-system-test
    2. Blackmagic Disk Speed Test https://itunes.apple.com/us/app/blackmagic-disk-speed-test/id425264550?mt=12
    3. AmorphousDiskMark - http://www.katsurashareware.com/pgs/adm.html - click download in upper left of page.
    4. Intech SpeedTools - https://eshop.macsales.com/item/Intech Software/STTPRO/

    Graphics Benchmarks:
    1. Cinebench - https://www.maxon.net/en/products/cinebench-r20-overview/
    2. Heaven - https://benchmark.unigine.com/heaven?lang=en#editions

    General Benchmarks:
    1. GeekBench 4 - https://www.geekbench.com/

    General Utilities:
    1. Intel Power Gadget - https://software.intel.com/en-us/articles/intel-power-gadget-20
    2. Drive Dx - https://binaryfruit.com/drivedx
    3. TRIM Enabler 4 - https://cindori.org/trimenabler/
    4. diglloydtools - https://diglloydtools.com/
    5. MacCPUID - https://software.intel.com/en-us/file/maccpuiddmg


    Magician Software for Samsung NVMe drive:
    - https://www.samsung.com/semiconductor/minisite/ssd/product/consumer/magician/
    - https://www.storagereview.com/samsung_magician_and_data_migration_overview
    - Overprovisioning is just a way to simply prevent you from overfilling your drive to an extent that it bogs down your drives performance. Even NvME drives and such can be bogged down if there's too much data on them, so simply put, 10% OP will just prevent you from utilizing that last 10% available storage on the drive, allowing the system to fully utilize the performance of the drive without it being slowed down by overloading of data.
    - Rapid Mode is only supported on Windows and SATA SSDs

    Diagnostic Tests/Verification of successful upgrade:
    1. https://support.apple.com/en-us/HT202731
    2. Reference codes: https://support.apple.com/en-us/HT203747
    3. How to Verify Your Mac’s Hardware Is Working Properly - https://www.intego.com/mac-security-blog/how-to-verify-your-macs-hardware-is-working-properly/
    4. Go to ‘About this Mac’ -> ‘System Report’ -> NVMExpress, make sure you see Link Width: x4, some have reported the slower Link Width: x2. This causes sub-optimal read/write speed, and is most likely secondary to a bad adapter.
    5. Activity Monitor - consider Content Caching enabled in the Sharing pane of System Preferences
    https://support.apple.com/en-us/HT201464#memory

    Troubleshooting:
    1. Reset SMC - https://support.apple.com/en-us/HT201295
    Ram issues? Reset SMC - https://forums.macrumors.com/threads/2017-imac-ram-issues.2182398/#post-27387165
    2. Reset PRAM & NVRAM - https://support.apple.com/en-us/HT204063
    3. Start up in safe mode - https://support.apple.com/en-us/HT201262


    5K Retina 27-inch iMac Service Manuals (The original Step-by-Step technical guides which Apple provides for Mac-certified technicians and the videos as a part of Apple training course for qualified Mac technicians):

    - 2017 Manual Only, https://www.ebay.com/itm/iMac-27-in...598326?hash=item1ef01f3e76:g:maYAAOSwc6ZcBtbr
    This is the actual 484 page service manual Apple provides to technicians. Costs $1.99 on Ebay, paid by PayPal. Authentic.
    - 2017 Manual and videos, https://www.ebay.com/itm/iMac-27-inch-Retina-5K-2017-Service-Technical-Guide-Video-Repairing-Course/132973174152?_trkparms=aid=333200&algo=COMP.MBE&ao=1&asc=20190129125700&meid=8152afdb8ff7486ba938f61cc35de598&pid=100752&rk=2&rkt=12&sd=132950790314&itm=132973174152&_trksid=p2047675.c100752.m1982
    - 2019 Manual: https://manuals.info.apple.com/MANUALS/1000/MA1859/en_US/imac-5k-27-inch-2019-repair.pdf


    Diagnostic LEDs (total of 5) are located along the upper right side of the logic board, just to the right of the display data cable connector.

    Diagnostic LEDs 1–5

    1 = AC input voltage (trickle power present)
    2 = Power supply DC output voltage
    3 = Memory is functioning
    4 = GPU is functioning
    5 = Display panel is connected


    Diagnostic LEDs

    LED 1

    • Indicates that the trickle voltage from the power supply has been detected by the main logic board. This LED will turn on when you connect the iMac to a working AC power source. The LED will remain on as long as the computer is on or asleep.
    • When the computer has been shut down correctly, LED 1 behavior may differ:
    - If a startup event is scheduled in System Preferences/Energy Saver, then LED 1 will stay on after a correct shutdown.

    - If no startup event is scheduled in System Preferences/Energy Saver, then LED 1 will turn off and will stay off as long as the power cord is kept connected and an AC power source is present. Disconnecting the power cord and plugging it back in will turn this LED back on, even if the computer is still off.​
    • After disconnecting and reconnecting the AC power source, this LED could remain off:
    - If the AC power source is missing or disconnected.
    - If the logic board is disconnected from the power supply or the AC receptacle.
    - If the power supply board is faulty.​

    LED 2

    • Indicates that the computer is turned on. This LED will be on as long as the computer is turned on (but is not asleep) and the power supply and voltage regulators are working correctly.

    LED 3

    • Indicates that the logic board and GPU are communicating. This LED will be on when the CPU is communicating properly with the GPU. If LEDs 1 and 2 are on and LED 3 is off, then the backup battery (on the back of the logic board) may need to be reseated or the logic board may need replacement.

    LED 4

    • Indicates that the logic board and LCD panel are communicating. This LED will be on when the computer is turned on and a video signal is being generated. If LED 4 is on and there is no image on the display, then the LCD panel or the cables between the LCD and logic board might be installed incorrectly or need replacement.

    LED 5

    • Indicates the logic board and LCD panel are communicating. This LED is on when the computer is turned on, a video signal is being generated, and the LCD Panel is signaling to turn on the backlight. If LED 5 is ON and there is no image on the display, then the LCD backlight or circuitry on the logic board may be malfunctioning. The LCD panel or the cables or the logic board may need replacement.



    LED Startup Sequence

    LED 1 = Power is available.

    If no LED is visible:

    o Disconnect the power cord from the computer and wait 15 seconds to reset the power supply and LED status. Reconnect the power cord and check the LED status again.​

    o Verify the AC source.​

    o Verify that a known-good power cord is connected.​

    o Verify the cable connection between the AC inlet and the power supply.​

    o Verify the cable connection between the power supply and the logic board.​

    o Verify the power supply.​

    LED 1 + LED 2 = Power is available and the system is turned on.

    If the second LED is not visible when the power button is pressed:

    o Verify that the power button is connected to the power supply.​

    o Verify power button functionality.​

    o Verify the cable connection between the power supply and the logic board.​

    o Verify the power supply.​

    o Verify the logic board.​

    LED 1 + LED 2 + LED 3 = Power is available, the system is turned on, and the GPU was found.

    If the third LED is not visible after the system is turned on:

    o Verify whether the fan is running when turned on (reset SMC and PRAM, verify backup battery voltage for proper startup).​

    - If the fan is not heard, go to the “No Startup” troubleshooting flow.​

    LED 1 + LED 2 + LED 3 + LED 4 = Power is available, the system is turned on, the logic board is communicating with the GPU, and the internal LCD was found.

    If the fourth LED is not visible after the system is turned on:

    o Verify the internal DisplayPort cable (eDP) connections between the LCD panel and the logic board.​

    o Inspect the LCD display cables for cable damage.​

    o Verify external video functionality and proceed according to the result:​

    - If an external display works, verify/replace the LCD panel.​

    - If an external display does not work, verify/replace the logic board.​

    LED 1 + LED 2 + LED 3 + LED 4 + LED 5 = Power is available, system is turned on, GPU is working, logic board is communicating with the LCD panel, and the LCD panel has turned on the LCD backlight.

    If the fifth LED is not visible after the computer is turned on:

    o Verify the internal DisplayPort cable and backlight cable connections between the LCD panel and the logic board.​

    o Inspect the LCD display cables for cable damage.​

    o Using a flashlight, check the following areas on the panel:​

    - Look in the top left corner of the panel to see if there is a dim Apple logo (the Apple menu logo).​

    - Look in the center of the panel to see if there is a login screen.​

    - Look at the bottom of the panel to see if there is a Dock visible.​

    - If the following items are visible, there may be something wrong with the display cables or the logic board. Proceed to the next step.​

    • Replace the LCD panel, check that all the LEDs are visible, and that the backlight functions. If the computer does not function after replacing the LCD panel, replace the logic board.


    Power-On Self-Test (POST)

    Intel-based Mac computers such as the iMac rely on a combination of tones and blinking LED lights to display Power-On Self-Test (POST) error codes.

    • If the computer detects out-of-specification or no Random-Access Memory (RAM), the screen will remain black but the computer will beep. This error condition may be due to physically damaged RAM, installing an incorrect type of RAM, or not having RAM installed.
    • Some RAM may appear to pass POST, but still cannot be used by the operating system. In this case, the computer will display a gray screen, sound three beeps and repeat beeps until computer is turned off.
    • The solution to both of these situations is to first reseat RAM and test computer again. If RAM fails POST again, remove all installed RAM and test by installing one by one each RAM module that has been verified to work correctly on another computer (“known-good” RAM, for example) or order new RAM.
    • A sequence of tones heard at startup or a no video symptom may also be fixed by temporarily removing/replacing the backup battery.
     

    Attached Files:

  2. macgeek01 macrumors 6502a

    Joined:
    Apr 2, 2013
    #2
    You have no sleep issues with 3rd party NVME?
     
  3. rxs0, Apr 13, 2019
    Last edited: May 18, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #3
    This is the painter's tape (adhesive side up) that I used to spatially organize the screws during disassembly. As mentioned above, you can also label the tape into grids with pen by component. From left to right, the screw groupings sort of parallel the spatial arrangement of iMac components, which are the right speaker, hard drive assembly, power supply, cooler, logic board with heatsink duct screws, wifi screws, and finally right speaker. Again, this really made reassembly very fast and easy.

    The guys in the first video used this magnetic "grid" project mat from ifixit.com as well as a flashlight and small magnet tool to capture screws. I included a screen shot of the tools the guys in the first video used for their installation. I tried to use the same setup.
    https://www.ifixit.com/Store/Tools/Magnetic-Project-Mat/IF145-167?o=4

    A "flexible" screwdriver may be better suited to loosen/tighten the (2) T8 torx screws on top of the heatsink duct. See picture below.

    When cutting the adhesive tape with the cutting wheel, avoid cutting around the camera area (see picture below). Cutting around the camera area can result in damage to the camera. Because there is no VHB adhesive al the top center, where the camera is located, there is no need for a continuous swipe across the top.

    Silicone Display Roller used to adhere the display adhesive strips to the glass.
    - Use the silicone display roller to adhere the display adhesive strips (on the sides of the display) to the glass. To prevent image quality issues, only roll upward.
    - Roll the silicone display roller along the top in a horizontal back-and-forth motion.
    - Roll the tool along the top and sides of the display panel. Move the tool back and forth until it moves with minimal resistance.

    Use the ifixit guide below and the YouTube videos above to guide your disassembly process.
    https://www.ifixit.com/Guide/iMac+Intel+27-Inch+Retina+5K+Display+CPU+Replacement/30515
    The YouTube videos do a much better job showing the reassembly process.

    --- Post Merged, Apr 13, 2019 ---
    Here are the pictures of my bent CPU. As you can see in the pictures, the bends are located in the chip board near the CPU notches. I left this CPU in this compressed bent state within the tightened heatsink/logic board assembly for about a week before I removed the CPU for repair. Surprisingly, there was no damage to the CPU socket pins on the logic board. The CPU worked flawlessly with no errors after I straightened out the bends in the CPU board. I was really prepared to spend another $350 to replace the bent CPU.

    I decided to go with the i7-7700 instead of the i7-7700k to avoid higher CPU TDP wattage and so fan noise. See post below.
     

    Attached Files:

  4. rxs0, Apr 13, 2019
    Last edited: Apr 24, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #4
    Here are the pictures showing the repaired unbent/straightened CPU against a white background. Again, I used a wooden handscrew clamp to gently unbend the CPU. I made at least 10 micro bends in the opposite direction/curvature in the wooden clamp to straighten the CPU board. I have included a picture of the logic board CPU socket which remains intact despite the bent CPU. Be sure to thoroughly wipe the CPU contacts with a microfiber cloth in case you accidentally get some thermal paste on the contacts.
    --- Post Merged, Apr 14, 2019 ---
    Here is a composite picture of the side profile of the CPU spring showing the curvature of the spring, original on the right, modified with less curvature and tension on the left. I again used the wooden clamp to partially straighten the spring with multiple microbends until I was satisfied with the residual spring tension and the more optimal alignment of screw holes. I gradually bent the spring so that I could easily manually secure all 4 mounting screws by hand and still maintain sufficient tension on the CPU heatsink assembly when the screws were fully tightened. You can practice this on a used CPU spring from Ebay if you are not comfortable performing this operation on your stock CPU spring. This video (at time 4:40) clearly shows the difficulty reassembling the CPU spring while trying to keep the heatsink assembly perfectly aligned. The CPU spring modification made this step easy.
    --- Post Merged, Apr 14, 2019 ---
    Although not entirely necessary, I taped the GPU bracket to the logic board with a piece of painter's tape to keep the bracket aligned with the logic board screw holes after removal and reapplication of the GPU screws. When I reassembled the GPU portion of the heatsink, all I had to do was screw in the GPU screws and pull off the tape. This was one less piece that I had to struggle with when reassembling the heatsink to the logic board.

    You can use a 1mm Thermal pad on the VRMs (Voltage Regulator Module). I just used Arctic Silver 5 Thermal Paste.
     

    Attached Files:

  5. rxs0, Apr 14, 2019
    Last edited: May 18, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #5
    This is the tiny ribbon cable (microphone cable) along the bottom right of the logic board, which is a new addition to the mid 2017 27-inch iMac. As you can see in the first image, I literally avulsed/tore off the delicate tab just along the connector. This doesn't result in any problems, but can be avoided if you don't attempt to disconnect cable by pulling back on tab. Just use your needle tip spudger to loosen the connector. The tab helps you align the connector during reconnecting the cable. I also used a small piece of tape to move the cable out of the way while I put the logic board back into the case.

    Heatsink duct flap lays over Cooler duct.

    Use spudger or antenna tool to gently pry off WIFI connectors.

    ---------------------------------------
    Display Panel - Replacing Very High Bond (VHB) Strips

    Apple kit used to reapply display.

    Technique used to remove residual adhesive using isopropyl alcohol wipe and spudger.

    Holes in chassis used to align adhesive strips with pointy side of spudger tool.

    Important: Start replacement with VHB strip 25. Align the small perforation (see the second image) on the VHB strip with the microphone hole on the chin. Important: Make sure to use the correct strip and line up the perforation with the microphone hole or it could lead to microphone issues.
    https://forums.macrumors.com/thread...itfalls-and-tips.2177812/page-2#post-27335688

    Each VHB strip has an ID number on the pull tab and part number (946-xxxx) printed on the strip. Use the picture below to verify that you have all of the needed VHB strips. Lay out the VHB strips before installing them onto the computer and check them for damage. Check that there are no wrinkles or exposed sections on the strip. Damage can cause cosmetic gap issues, make the display bond weak, or create light leakage.

    The bottom right strip labeled 25 for iMac (2017) has a perforation in the VHB for the microphone hole. Make sure to use the correct strip and to line up the perforation with the microphone hole or it could lead to microphone issues.

    The VHB strips have a foam layer (VHB/foam/VHB), with a removable liner on the underside and a clear plastic liner on the top side. Be careful peeling the paper liner off the underside of the VHB strip. Note: The color of the removeable liner may vary between VHB vendors.

    The rear housing has eight alignment holes. Use them to align the new VHB strips with the pointy tip of the spudger tool.

    Before adhering the VHB strips and installing the display, verify that all cables are connected, all screws are installed, and that there is no debris present in the computer.

    Peel the paper backing off of one portion of the VHB strip. Note: The more recent VHB strips are a teal blue color. Some of the procedures that follow show older VHB strips, which are an orange color. The replacement VHB process is the same regardless of color.

    Use the pointed end of a black stick to align the VHB strips on the rear housing. The paper liner side faces the rear housing.

    Use the pull tab on the back of the display adhesive strip to remove the top portion of the paper liner. Leave the remaining paper liner on the bottom portion of the strip.

    As you position the VHB, use your finger to peel the remaining paper liner from the underside of the VHB strip.

    Use your finger to press the VHB strip into place on the rear housing. If a VHB strip does not line up correctly, remove it and start again.

    Do not remove the clear plastic liners from the top layer of the strip at this time. Remove them right before you replace the panel.

    Insert the pointed end of a black stick into another alignment hole and peel the paper backing off of the strip. Press down with your finger to adhere the strip to the rear housing.

    Repeat the VHB process (align, peel paper liners, press VHB into place) along the top edge of the rear housing. Press with your fingers to adhere the strips to the rear housing.

    Two strips of VHB are used along the bottom edge. There are no guide holes on the VHB strip or rear housing for the bottom strips. Align the strips carefully by hand.

    Important: The bottom VHB strips on the iMac (2017) are different from the bottom strips on the iMac (Late 2015) and older models. The bottom right strip labeled 25 for iMac (2017) has a perforation in the VHB for the microphone hole, refer to image below. Make sure to use the correct strip and line up the perforation with the microphone hole or it could lead to microphone issues.

    -----------------------------------

    Display Panel Reassembly

    Insert the service wedge to hold the display steady for this procedure. When positioned correctly, the wedge covers the power receptacle.

    Place the display panel on the chin of the rear housing. Align the panel and check that it is centered and seated.

    Use the display removal tool to check the alignment on both sides of the display. Adjust if necessary.

    Anchor the display with a strip of painter’s tape. Place it over the bottom of the display and the edge of the rear housing.

    Anchor the display further with more strips of painter’s tape. Place one or two vertical pieces along the edge for added support.

    Use one hand to tilt the display forward.

    Use the other hand to pull the clear release liners on the bottom VHB strips. Pull the release liners carefully so they do not tear or break.

    Be extremely careful not to stress the display cables and connectors on the logic board when tilting the display open. The display connectors on the logic board are easily damaged. If the connectors are damaged, then the logic board will need to be replaced.

    Remove the remaining release liners from the top and sides of the display panel.

    After all the release liners have been removed, lower the display panel against the rear housing.

    Use the silicone display roller to adhere the VHB strips to the glass. Roll the edges of the glass panel from the bottom to the top. Do not roll up and down.

    Repeat the rolling along the top and the other side.
     

    Attached Files:

  6. Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #6
    Looking at all this, the thought that comes to mind:
    Some jobs just ain't worth it...
     
  7. rxs0, Apr 14, 2019
    Last edited: May 19, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #7
    Other installation tips:
    Metallic Spacers/Standoffs:
    This part of the installation deals with the (2) T25 spacer standoffs that are seen in the images below.

    The upper spacer, known as the "hard drive standoff", (with the longer screw) is used to bolt down the lower hole of the right hard drive bracket. This can be loosened and left in place to allow bracket to be flipped out of the way. The leftmost logic board screw is then screwed into this spacer.

    The lower spacer, known as the "power supply standoff", (with the shorter screw) is used to bolt down the small left black tab of the heatsink duct assembly (yellow arrow in images). The upper right power supply screw is then screwed to this spacer.

    As a side note, the SATA cable runs on top of the heatsink duct, and under the right hard drive bracket as in the picture below.

    Diagnostic LEDs:
    The location of the diagnostic LEDs are now on the upper right corner of the logic board as in the pictures below.
    - The first picture is with the system connected to AC power and the computer turned off. Only the leftmost green LED is on.
    - The second picture is with the computer turned on, fully booted up. All 5 green LED lights on.
     

    Attached Files:

  8. russofris macrumors regular

    Joined:
    Mar 20, 2012
    #8
    Indeed, though I'm glad that somebody did the job, so that we can analyze their results and make that determination.
     
  9. adamk77 macrumors 6502a

    adamk77

    Joined:
    Jan 6, 2008
    #9
    This is seriously impressive @rxs0.

    You said that you upgraded the CPU to the quad core i7-7700. Can I ask why you decided to go with that instead of the hexa core i7-8700K? I thought that the two CPUs share the same socket, so I would think you'd go with the more powerful chip as this is the kind of upgrade I would not want to repeat.

    Seeing as how 2019 iMacs with the i9 is performing adequately in the 2017 case, I would hazard a guess that the 8700K would be fine even with the higher TDP.

    Beyond cost and thermals, was there a deeper reason?

    Edit: How long did this take?
     
  10. rxs0, Apr 14, 2019
    Last edited: Apr 16, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #10
    Thank you adamk77. The 2017 27-inch logic board only supports the 7th Generation Intel processors. The i7-8700k is an 8th Generation processor.

    https://www.ifixit.com/Answers/View/437246/New+iMac+5k+2017+CPU+is+Upgradable
    https://www.ifixit.com/Answers/View...rade+to+i7-8700k+with+the+latest+OS+or+Mojave

    You could use the Intel i7-7700k CPU with base clock of 4.20 GHz and TDP of 91 W. I opted to use the less fast i7-7700 CPU with base clock of 3.60 GHZ with a TDP of 65 W to avoid overheating the system as there were some reports of the fan kicking in alot with the higher wattage i7-7700k version.

    The initial install took about 2 hours. After learning the system, I can easily do this in less than a hour. Don't rush.
    Take care.
     
  11. Zdigital2015 macrumors 65816

    Joined:
    Jul 14, 2015
    Location:
    East Coast, United States
    #11
    The i7-7700 and the i7-8700K share the same socket (LGA-1151), but they are not electrically compatible, nor does the 8700K use the Z170 PCH that the 2017 iMac uses, they are not compatible either, as the 8700K requires a 300-Series PCH, while the 7700 can use the 100-Series or 200-Series PCH. Hope this clears it up.
     
  12. rxs0, Apr 14, 2019
    Last edited: May 21, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #12
    Display removal and reassembly:

    pending
     

    Attached Files:

  13. macgeek01, Apr 14, 2019
    Last edited: Apr 14, 2019

    macgeek01 macrumors 6502a

    Joined:
    Apr 2, 2013
    #13
    I’ve done the same upgrades. I imagine you have sleep/standby issues with your NVME?
     
  14. macgeek01 macrumors 6502a

    Joined:
    Apr 2, 2013
  15. rxs0, Apr 14, 2019
    Last edited: Apr 14, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #15
    Hi macgeek01,
    I am currently out of town. I'll test the system more completely soon.

    I see you have the 2017 27-inch iMac in your profile. Any other problems?

    I am aware of the sleep issue. I'll update you soon.

    Thanks.
     
  16. rxs0, Apr 14, 2019
    Last edited: May 26, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #16
    Logic Board Cable connectors:

    iFixit Terminology - Apple Terminology
    Fan Cable Connector - Fan Cable
    iSight Camera Cable - Camera Cable
    Left Speaker Cable - Left Speaker Cable
    Power Supply Control Cable - Power Supply Signal Cable
    Power Button Cable Connector - Power Button Cable
    Right Speaker Cable Connector - Right Speaker Cable
    Headphone Cable Connector - Audio Cable
    Microphone Cable - Microphone Flex Cable
    Display Data Cable Connector - eDP (Embedded DisplayPort) Cable
    Display Power Cable Connector - Display Backlight Power Cable
    SATA Cable - Hard Drive Data and Power Cable
    Bluetooth/WIFI - (1) Wi-Fi antenna in silver circle behind Apple logo (2) Bluetooth (3) Middle WIFI (4) Lower WIFI

    Note that the mid 2017 27-inch iMac differs from the 2015 27-inch iMac ifixit repair guide by the addition of:
    1. Thin ribbon microphone cable (Apple calls this the "microphone flex cable") along the bottom right of the logic board. Caution: Do not damage the microphone flex cable. A broken microphone flex cable requires a rear housing replacement!
    2. The WIFI cables are now mounted in place with (4) small metallic tabs, (2) overlapping on the left, (2) overlapping on the right, with each overlapping pair fixed in place with a tiny retaining T5 torx screw. Update: It turns out that these WIFI/Bluetooth screws and retaining clips were present in the late 2015 iMac 27-inch.

    See pictures in this post.
     

    Attached Files:

  17. rxs0, Apr 14, 2019
    Last edited: May 13, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #17
    Power Supply:

    Connectors:
    As mentioned earlier, be sure to depress the connector latch locking the Power Supply DC Power and AC Inlet Cable connectors (on the front side of the power supply) when removing connectors.

    Power Supply Cover (923-0189):
    See picture below (in this case on an iMac Pro). This temporary cover is used to prevent electrical shorting during servicing or accidental touching of the contacts along the back of the power supply.
     

    Attached Files:

  18. mbosse macrumors 6502

    Joined:
    Apr 29, 2015
    Location:
    Vienna, Austria
    #18
    Awesome thread. This would interest me as well.

    Thanks,
    Magnus
     
  19. rxs0, Apr 15, 2019
    Last edited: Apr 24, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #19
    Important tips:

    Post from R.T. on ifixit forum, link below, regarding possible electrical shorting related to the NVME adapter.

    Although the newer Sintech adapters already have insulating tape on them, this tape can be easily pulled back and cut by the metal shield of the Apple NVME connector. I strongly recommend the use of Kapton tape as additional protection and isolation of the Sintech Electrical connectors. Please see post #33.

    Update:

    Don't use this short adapter: https://www.amazon.com/Sintech-Adapter-Upgrade-2013-2016-2013-2015/dp/B07FYY3H5F/ref=cm_cr_arp_d_product_top?ie=UTF8

    Use this long adapter: https://www.amazon.com/gp/product/B01CWWAENG/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

    https://www.ifixit.com/Answers/View/411888/NVME+M.2+SSD+with+adapter

    "I installed a Samsung 970 EVO 2TB M.2 in my mid-2017 27” 5k iMac and it works great with 4x NMVe speeds.
    You can use the adapters from the MacBook Air etc… with your 5k mid-2017 iMac … and you will get NVMe 4x speeds with a 4x lane drive . Physically the adapters are the same (different protocols ACHI vs NVMe with same pinout).
    I haven’t seen this posted anywhere, but the newer sockets on this logic board have an extended shield that can easily shorts to the adapter header. I confirmed with my multimeter. This can short out the power rails and most of the PCIE bus! This would help explain why some people have issues (failure to start and crashing).
    I used Kapton tape (electrical tape works also, but is not as clean). You want to cover the soldered header pins on the adapter socket on the mating side but obviously not the gold plated card edge pins. See attachment."
    From R.T.
     

    Attached Files:

  20. rxs0, Apr 16, 2019
    Last edited: May 11, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #20
    Testing system with 2TB Samsung NVME 970 EVO drive.

    There are numerous reports of the Samsung NVME 970 EVO PLUS version not being compatible with the Sintech adapter and iMac system.

    I initially used the OWC In-Line Thermal Sensor HDD Upgrade Cable as there was at least one report of someone having continuous loud fan noise in a similar upgrade, with Apple SSD drive removed and replaced with a Samsung NVME drive. I however did NOT have any loud fan noise without the device installed. :) I opted to not install the device.

    I am not having any sleep problems. I have included a screenshot of my power settings. The system has been running stable with no crashes.

    Software installation: The NVME drive was first initialized, erased/reformated to the APFS filesystem, and named Macintosh HD with the Disk Utility. I previously used the Carbon Copy Cloner application to copy my old fusion drive image to a new drive image prior to any disassembly of the iMac. This image was then copied to the new Samsung EVO 970 NVME drive using Carbon Copy Cloner on my MacBook Pro laptop, with the Samsung NVME 2TB drive installed within a USB 3.1 enclosure (Sabrent USB 3.1 Aluminum Enclosure for M.2 NVMe SSD in Gray (EC-NVME)). This drive also includes a USB C connector.

    I then tested this NVME drive (with newly installed Mojave OS) in this same Sabrent enclosure connected to the iMac via USB by booting the iMac off of the USB drive while holding the "option" key to confirm the drive image was intact and bootable. I was able to seamlessly install this drive with bootable software without any additional software setup on the iMac after installation of the NVME drive. The NVME drive was ready to boot up once installed on the logic board via the Sintech adapter.

    Sabrent USB 3.1 Aluminum Enclosure for M.2 NVMe SSD in Gray (EC-NVME)
    https://www.amazon.com/Sabrent-Alum...+3.1&qid=1555094958&s=gateway&sr=8-3-fkmrnull

    EKWB EK-M.2 NVMe Heatsink- Black
    https://www.amazon.com/gp/product/B073RHHYCM/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
    https://www.ekwb.com/shop/ek-m-2-nvme-heatsink-black#ow_alert_box

    Installation with this heatsink was tight using the short Sintech adapter, which I again don't recommend.

    I ended up having to replace the stock Apple screw securing the NVME drive with a 3rd party screw with a more conical flat head shape. I ended up using one of the included screws (M2 6mm) which came with the Sabrent NVME drive enclosure, which fit perfectly. You need to use a slightly LONGER screw with a slightly NARROWER head. The thickness of the adapter+heat sink is too much for the original screw. See picture below, Apple stock screw on left, Sabrent flat head screw on right. Both the Apple and Sabrent NVME screws use the T8 torx screwdriver.

    Getting the EKWB mounting springs installed was a real pain. Note that each clip has a "locking hook" or hinge and a "snapping hook" on each end. First secure the "locking hook", then snap the "snapping hook" in place. You may have to slightly bend the clip to accommodate the assembly. Also, orient both clips so that the matching type of hooks are on the same side. Align the clips with the matching notches in the bottom plate.

    Using scissors, cut the top 1mm thermal pad to length of the NVMe drive, long enough to cover the controller and NAND chips. Cut the bottom 0.5mm thermal pad to run the length of the bottom plate, just short of the mounting hole.

    Don't forget to remove the transparent protector film from both sides of the thermal pads prior to applying thermal pads to drive assembly. That is, remove the clear and blue liners from both sides of the 2 pads. I put the sticky side of the 1mm pad towards the heat sink. It is very difficult to remove the protective film off of the pads and may require the use of tweezers.

    Update: I ended using the long version of the Sintech adapter. See post below.

    The included thermal pads are different sizes, top pad is 1mm, bottom pad is 0.5mm). Put the sticky side of the 1mm pad towards the heat sink. To install NVME heatsink, you "sandwich" the assembly as follows: heatsink bottom, the included 0.5mm thermal pad, NVME drive, 1mm thermal pad, heatsink top, and hold it all together with the clips on notches on the side. Use a tweezer/screwdriver to lift the clip in place.

    I did not remove the copper label from the drive, as this acts as a heatsink. Removal of the labels will void your warranty. The Samsung 970 EVO NVMe Phoenix controller has a layer of nickel that helps dissipate heat faster.

    Be careful how you align the heatsink, so it doesn't cover the connectors or the screw hole on the other side. Please see post #33. Lastly, remove the small round protective film covering the heatsink logo.

    Samsung 970 EVO 2TB - NVMe PCIe M.2 2280 SSD (MZ-V7E2T0BW), Black/Red
    https://www.amazon.com/gp/product/B07C8Y31G1/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
    http://www.thessdreview.com/our-rev...-review-500gb-1tb-evo-becomes-a-top-tier-ssd/

    Update: Don't use this short adapter. Sintech NGFF M.2 nVME SSD Adapter Card for Upgrade MacBook Air(2013-2016 Year) and Mac PRO(Late 2013-2015 Year)
    https://www.amazon.com/gp/product/B07FYY3H5F/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

    Use this adapter:
    Sintech NGFF M.2 nVME SSD Adapter Card for Upgrade 2013-2015 Year Macs(Not Fit Early 2013 MacBook Pro)
    https://www.amazon.com/gp/product/B01CWWAENG/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

    OWC in-Line Digital Thermal Sensor HDD Upgrade Cable and Install Tools for iMac 2012, (OWCDIYIMACHDD12)
    https://www.amazon.com/gp/product/B00J42HP9O/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1
    Update: I did not need this device. I did not encounter and loud fan issues without this device installed.

    Thanks.
     

    Attached Files:

  21. macgeek01 macrumors 6502a

    Joined:
    Apr 2, 2013
    #21
    Your NVME is only negotiating with a x2 link opposed to x4 for some reason. I’m getting around 2700Mbps read and writes with a 2TB Sabrent Rocket on my Late 2015 27” iMac with x4.


    As far as sleep and standby it doesn’t seem that anyone has really reported success with 3rd party NVME in this thread but not sure if anyone was working with a 2017 like you:

    https://forums.macrumors.com/threads/a-list-of-successful-imac-27-ssd-upgrades.2162435/

    So you have no issues if select “Sleep” from the Apple drop down menu and then wait for sometime to wake?

    Please post your power management settings by running the command “sudo pmset -g” from the terminal (without the quotations.

    To see if your iMac supports sleep, standby, and hibernate please note your current settings then test with these settings then put into sleep and wait a few moments before attempting to wake.

    Test 1: sudo pmset -a standbydelay 0

    Test 2: sudo pmset -a standby 0 with sudo pmset -a hibernatemode 0

    You can then use the same commands to set back your original settings. If anything you can set back the defaults from nevertheless settings in system preferences then test from there.

    Thanks!
     
  22. rxs0, Apr 17, 2019
    Last edited: May 14, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #22
    Hi macgeek01,
    For some reason, my Samsung EVO 970 2TB drive is only negotiating a Link Width of x2 instead of x4. My firmware seems to be up to date. Update: The short Sintech adapter was only able to negotiate a x2 Link Width speed. The long Sintech adapter correctly negotiated a x4 speed. See posts below.


    Model Name: iMac
    Model Identifier: iMac18,3
    Processor Name: Intel Core i7
    Processor Speed: 3.6 GHz
    Number of Processors: 1
    Total Number of Cores: 4
    L2 Cache (per Core): 256 KB
    L3 Cache: 8 MB
    Memory: 8 GB

    Boot ROM Version: 170.0.0.0.0
    SMC Version (system): 2.41f1

    Update:
    New firmware as of May 13, 2019:
    Boot ROM Version: 172.0.0.0.0

    SMC Version (system): 2.41f1


    I think the problem lies with the Sintech adapter and/or Samsung 2TB EVO 970 NVME drive.
    - I tried booting the iMac off a fresh installation of Mojave on a 1TB Samsung EVO 970 drive (using the Sabrent NVME USB drive enclosure), with no luck. The 2TB EVO 970 drive was still recognized as a x2 Link Width drive.
    - I even swapped out my RAM to the original 8GB RAM with no luck.
    - I tried erasing the drive and reformatting it to APFS, and then reinstalling a fresh Mojave install using the "command r" recovery mode route. No luck.

    I am going to try to swap out the adapter and drive in the coming weeks. I also ordered the
    https://www.amazon.com/gp/product/B01NBAWWFL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
    Apple Genuine SSD 512 GB NVMe Flash Storage Upgrade Kit for MacBook Pro Retina, Mac Pro, iMac Models. MZ-KKW5120 655-1994A.

    I again am not experiencing any sleep problems. I tried the Apple -> Sleep option with no problems.

    I'll update you with my progress.

    Thanks.
     
  23. macgeek01 macrumors 6502a

    Joined:
    Apr 2, 2013
    #23
    Cool, will be interesting to find out if you can also enter standby and hibernate with the Samsung NVME.
     
  24. rxs0, Apr 18, 2019
    Last edited: Apr 18, 2019

    rxs0 thread starter macrumors member

    rxs0

    Joined:
    Apr 4, 2019
    #24
    $ sudo pmset -g

    Password:
    System-wide power settings:
    Currently in use:
    Sleep On Power Button 1
    autopoweroff 1
    standbydelayhigh 86400
    autopoweroffdelay 28800
    proximitywake 1
    standby 1
    standbydelaylow 86400
    ttyskeepawake 1
    hibernatemode 0
    powernap 1
    gpuswitch 2
    hibernatefile /var/vm/sleepimage
    highstandbythreshold 50
    displaysleep 1
    womp 1
    networkoversleep 0
    sleep 1
    tcpkeepalive 1
    halfdim 1
    autorestart 0
    disksleep 10

    Commands below performed:
    sudo pmset -a standbydelay 0
    sudo pmset -a standby 0
    sudo pmset -a hibernatemode 0

    No sleep problems.
    Thanks.
     
  25. macgeek01 macrumors 6502a

    Joined:
    Apr 2, 2013
    #25
    Thanks for testing! Please also test standby 0 with hibernatemode 25 if you get a chance. Thanks again.
     

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