Replacement Seagate HDD

Discussion in 'iMac' started by skuid87, May 24, 2012.

  1. skuid87 macrumors regular

    Apr 2, 2012
    Hi all,

    The HDD has failed on my 21.5" Intel iMac. It's out of warranty so I can't get Apple/Authorised Repair center to replace it for free.

    I've opened up/serviced a few macs already (including iMacs) before, so I'm confortable with the process.

    The only think I'm unsure about is which HDD to buy as a replacement. I know there are issues with the way these iMacs check temp, so the replacement drive has to be from the same manufacturer.

    But does it also have to be the exact same model? The current HDD in this iMac is a 1TB ST31000528ASQ.

    I've seen various 1TB Seagate Barracuda 7200rpm drives out there, but they don't necessariy match that exact model number. Is that an issue?

    For example, would this ST31000524AS or this ST1000DM003 be ok?

    Thanks in advance for your help.
  2. brand macrumors 601


    Oct 3, 2006
    Any 3.5" SATA hard drive or solid state drive.
    Any 2.5" SATA hard drive or solid state drive along with an adapter.
  3. skuid87 thread starter macrumors regular

    Apr 2, 2012
    Thanks for your reply, but that isn't what I was after.

    I shoud have been clearer in my original post. I understand that any SATA drive will work. But if you use a drive that isn't from the same manufacturer, it will cause an issue with the fans spinning at full speed due to the temp sensor built into the drive.

    I want to avoid this problem by using a drive that uses the same temp sensor as the stock one.

    My question was if all of the Seagate Barracuda drives use the same temp sensor. Or do I need to buy the EXACT same model number?

  4. wagsrules macrumors newbie

    Dec 18, 2011
    I sure apple uses custom firmware on their harddrives. The only way to avoid any problems is to get a harddrive through apple.

    Someone correct me if I'm wrong.
  5. GyroFX macrumors 6502

    Jan 14, 2002
    Los Angeles and NorCal
    I recently had to replace my 27" imac's seagate HD. I replaced it with ST1000DM003. I believe since it does not have the apple firmware, like the OE Apple Seagate HD, the temperature sensors has trouble knowing when to spin the fan up. The fan doesn't spin up but the temp sensors do work. I had to use fan control preference app and some terminal scripts to make the fans auto detect temp and set fan speeds.
  6. skuid87 thread starter macrumors regular

    Apr 2, 2012
    Could you provide details on how I could do this please?
  7. GyroFX macrumors 6502

    Jan 14, 2002
    Los Angeles and NorCal
  8. skuid87 thread starter macrumors regular

    Apr 2, 2012
    Hi, thanks for your advice guys.

    I took the iMac into the local Apple Store and had a chat with a couple of the genius' there about replacing the HDD myself. They said I could use ANY 3.5" SATA Drive and the only thing I should consider is to get a drive with the same speed (rpm) as the current HDD. One genius even recommended I get a Hitachi drive!

    When I mentioned the temp sensor, one genius had no idea (the same one who recommended a Hitachi drive). The other said I should get a HDD from the same manufacturer as the one currently installed. He said it wouldnt have to be the EXACT model.

    I then asked him if Apple place a custom firmware on the HDD's that they install. He seemed fairly sure that this wasn't the case.

    So I've ordered a replacement drive (same manufacturer). Let's see what happens...

    Either the firmware issue is a myth, or the Genius' don't know what they're talking about!
  9. bikemd macrumors newbie

    Jul 3, 2012
    Calgary, AB, Canada

    Can you give me an update on how this worked out? I am in the same situation. I have a late 2009 iMac that I need to replace the HD on. My iMac also happen to have a Seagate internal drive which is identical to yours. Presently, I am going through the same research that you did but unsure of a few things. I do plan to get a new Seagate model to swap out the old one. I also know that the temp sensor connector needs to be the same. I hope you've done your upgrade by now and can enlighten me with a few things:

    • I am hoping to swap in a Seagate ST1000DM003 or ST2000DM001. Should they have the same connector as the original Seagate inside our 2009 iMacs?
    • Which HD did you buy?
    • Did you have any issues with the connector?
    • Did you have any issues with the temperature sensing/fan control?
    • Any other tips?

    Thanks. Looking forward to learn from you.
  10. skuid87 thread starter macrumors regular

    Apr 2, 2012

    I have indeed completed the repair. Was very straightforward and the used a HDD with identical temp sensor. I can't speak for your HDD but I used the ST31000524AS.

    Good news is that HDD worked perfectly. Formatted it and installed Lion without any problems at all.

    Bad news - The fans will slowly spin up to max speed and stay there. Looks like Apple do indeed use a firmware that isn't available publicly.

    There is a workaround. It costs £20.

    Good thing about this is that it doesn't just spin the fans down and keep em quiet. It actually works out how to measure the temp of the HDD and adjust the speed accordingly (i.e what it should be doing!).

    I hope this helps... Any questions, let me know.
  11. ibarnett macrumors regular


    Aug 20, 2010
    Gold Coast, Australia
    I have been reading this thread with interest.
    I read another thread (which I can no longer find), where it was suggested to buy the same brand drive & swap the circuit boards.
    I am sceptical about this - does anyone know if this is indeed feasible/do-able???
  12. bikemd macrumors newbie

    Jul 3, 2012
    Calgary, AB, Canada
    Since my post asking the questions below, I have swapped out my internal HD with the Seagate ST2000DM001 model. I thought I would now answer my own questions in case it helps someone else.

  13. randym431, Oct 7, 2012
    Last edited: Oct 7, 2012

    randym431 macrumors newbie

    Mar 29, 2011
    I just wanted to add my own experience.
    I wanted to do this too, upgrade from the 1TB to the 2TB drive in an iMac EMC 2374. A very popular and a bit older 27" iMac.

    Other than this post, I found it near impossible to determine the correct hard drive to use for success.

    My replacement went like clock work. More smoothly than I ever imagined.

    I use the Seagate Barracuda STBD2000101 drive, available from my local Best Buy. This drive has the 4 pin thermal connector. An 2TB drive that works flawlessly in the 27" iMac EMC 2374.

    All I did was go over to my local Home Depot and buy 2 "Brutus Suction Cups" Model # 75000-6, Store SKU # 253240 for $6.98 each. They are heavy duty 4.5" rubber suction cups.
    I also bought at Home Depot the "Husky 8-IN-1 Torx Screwdriver Set" Model # 74502, Store SKU # 165355 for $5.97.
    This has the 2 Torx drivers you need, in this set.

    I followed the various online examples to remove the iMac screen to get to the hard drive. Mainly, I followed the instructions from the below linked web site to dismantle the iMac.

    To make the switch, I wanted to "FIRST" make sure I had a current TIME MACHINE backup, to restore from after the hard drive switch. So you should make sure you do a Time Machine backup before pulling the power plug and swapping out the hard drives.
    Naturally, TIME MACHINE backup to an ""EXTERNAL HARD DRIVE"".
    I used the "Iomega 2TB external firewire hard drive - mac version" for the time machine backup.
    (My normally used time machine drive.)

    I then followed the guide from the website (linked above) to replace the 1TB with my new Best Buy Seagate Barracuda STBD2000101 2TB hard drive.

    I put the iMac back together.
    Grabbed my iMac Install DVD, turned on the iMac and inserted the DVD.
    Then I had to manually power-OFF the iMac and power-ON while holding down the "C" key on the keyboard, so that the iMAc would boot from the "mac os x install DVD".
    (otherwise the system comes up eventually with only a flashing FOLDER icon, if you try to power on the iMac not using the original INSTALL DVD.

    So booting holding down the "C" key with the install DVD, the system finally comes up with the install screen after some time waiting.
    You can hear the DVD clicking and booting as it loads up.
    Then, when the DVD loads you will have to select your language and continue.

    DO NOT install the mac OS from the boot DVD.
    If you look to the upper left of your screen you see the menu selections.
    Select utilities and DISK UTILITIES to PARTITION your new 2TB hard drive.
    On mine, I just made one big 2TB partition.
    You can split up the hard drive real-estate into more than one partitions, if you desire.

    Label the main partition name ""Macintosh HD"" as was it labeled originally on the old 1TB hard drive.
    After making the partition, I went back into the upper top left UTILITIES menu and at the bottom it says to "restore from time machine backup".
    I attached my TIME MACHINE Iomega external firewire hard drive to the iMac firewire port.
    It then shows up in the list of drives on the machine.
    Select that Time Machine backup drive, and start the backup to your new 2TB hard drive.

    That process took about 7 hours to restore the full backup onto the new drive.

    After the time machine restore is done, it prompts you to RESTART.
    Select "restart", and let the machine boot.
    DO NOT hold down any keys this time.
    You DO NOT want to boot from the DVD again. So hold no keys down.

    My iMac booted up looking just as it did when the old original 1TB drive was in the machine.
    Eject the iMac Install DVD (you are done with that) and you should now have your iMac running with a brand new 2TB hard drive.

    iTunes came up and worked. Everything looking fine.
    BUT... for some reason when I started "MAIL", it wanted me to create new accounts. As if this was the first time I ever used MAIL on this iMAc.
    No idea why.
    If anyone knows why, please post.

    Actually i spoke too soon. "MAIL" simply imported all of my info on its own.
    I did not need to re-create my account(s).
  14. iSayuSay macrumors 68040


    Feb 6, 2011
    If you're in US or nearby, you can order a custom HDD for iMac from iFixit. 1 TB or 2 TB, and I believe they sell the same exact HDD used for iMac so you don't have to worry about temp. sensors or anything.
    It's cheaper too than having Apple replace it for you.
  15. randym431, Oct 7, 2012
    Last edited: Oct 7, 2012

    randym431 macrumors newbie

    Mar 29, 2011
    Well I just wanted to post my all-in-one experience guide as to not only finding a hard drive THAT WORKS for the 2TB upgrade, and has the necessary thermal 4 pin sensor, and the 2TB drive is around $100, and should be available from your local Best Buy store.

    And I wanted to add my experience to the post originally started by skuid87 and updated by bikemd, because bikemd also seems to have found a workable 2TB hard drive brand.

    But I also wanted to give a heads up on where to get ALL the needed tools, cheap, and locally.

    And after the physical drive has been updated, how to restore your Time Machine backup onto the new drive.
    Yes... it can be easily done.

    1TB upgrade to 2TB. Restoring your Time Machine backup from the 1TB drive to the new blank 2TB drive.
    And other than the extra hard drive real estate you will gain, everything else looks, feels, acts and runs the very same after restoring your Time Machine backup to the new 2TB drive.

    Finding straight forward info on all of these steps was a real challenge. Even for Google.
    Plenty of "dis assemble" guides around. But no one seemed to know what exact 2TB hard drive to use.
    And no one seemed to know if your current Time Machine backup could be restored onto the new 2TB drive.
    Hope this helps iMac owners.
    A lot cheaper than buying a new $3000 iMac, just to get a larger hard drive.
    (which I was almost ready to do)

    Note: My system was the iMac 27" model: EMC 2374, that I upgraded.
  16. randym431 macrumors newbie

    Mar 29, 2011
    Oh... by the way...
    Hold onto your original iMac 27" EMC 2374 factory 1TB hard drive.
    Just as a safe guard.
  17. robvas macrumors 68030

    Mar 29, 2009
    You can just use a plastic credit card or knife (or even your fingernails) to pop the screen off.

    As far as the fans - download SMCfan control and then use this script to turn the speed down:

    /applications/ -k F1Mx -w 1500

    I have set it as low as 1000 and as high as 2000 and not been able to hear the fans.
  18. Lonewolf61 macrumors newbie

    Aug 3, 2017
    Hulst (NL)
    I still miss how you connected the 2 wires (in original 6 pole connector) to the 4 pin connector on the new HD..? I am currently doing more or less the same thing.
  19. gczychi macrumors newbie


    Aug 4, 2017
    I'm also having the same question. And I have some information.

    First of all, my iMac 27" is a Mid-2010 model, MC510LL/A - iMac11,3 - A1312 - 2390

    It receives the temperature through a special cable that goes into an extra slot into the hard drive (see picture 1 below):

    I presume that it just connects to a thermal resistor and my question is: Can I just put a thermal resistor between the two pins that go into the iMac motherboard? And if so, what kind of resistor would that be?

    Here is some other information that might be helpful:
    OWC sells a cable that you could use in your iMac, but it is oddly designed. Apparently it draws power from the hard drive connector that goes into a small circuit board where there is a thermal resistor (apparently — the picture is very bad). This cable costs $39,99 (OWC cable).

    This page shows a similar construction to the OWC board and gives a very good breakdown of Apple’s use of thermal fan control.

    Any ideas of using just a thermal resistor instead of the OWC board?



    Picture 1:

    Picture 2 (OWC thermal board):
    --- Post Merged, Aug 4, 2017 ---
    see also

    There are two solutions: The first ist to solder a Transistor 2N3904 to the leftover cable when you replace the hard drive and the second solution is to use a thermal resistor of an older Mac.

    I have no idea why the Transistor should work?

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