Dead 5k iMac

[glenthompson]

My wife’s 2017 5k iMac seems to be dead. When powered on, nothing appears on the screen but the wired keyboard lights up so it’s getting power. Putting my ear to the case I can hear something running but unsure if it’s the fan or HDD (fusion drive). No indication of anything on the screen and no apparent backlight. I’ve tried the procedures for SMC and NVRAM resets but no difference.

This happened after rebooting due to a MacOS update (High Sierra). I had been making a new backup that was taking awhile. After bugging me to install the update, I finally told it to install it after the new backup was complete. Left it alone to go do other stuff and when I checked back some hours later, the screen was black and wouldn’t wake up. Tried the resets and multiple reboots but nothing. Any suggestions of what to try before taking it to Apple? I’m at a loss.

 

[mannyvel]

Try plugging a monitor into it and see if anything shows up on the screen. You can also try putting it into target disk mode and seeing if the drive comes up on another Mac; just push the T key and power it on.

 

[Fishrrman]

I'm wondering if it could have been a "failed firmware update" during the upgrade?

Do you have a "brick n mortar" Apple Store anywhere nearby?
If nothing else works, sounds like it's time for a trip to the genius bar.

 

[glenthompson]

I'm wondering if it could have been a "failed firmware update" during the upgrade?

Do you have a "brick n mortar" Apple Store anywhere nearby?
If nothing else works, sounds like it's time for a trip to the genius bar.

Apple store is about an hour away - I'm in between two, each about the same distance. The failed firmware or something in the update was one of my thoughts.

 

[glenthompson]

Try plugging a monitor into it and see if anything shows up on the screen. You can also try putting it into target disk mode and seeing if the drive comes up on another Mac; just push the T key and power it on.

It's USB-C and the only monitors I have are my Thunderbolt display and an old Cinema display, neither of which will work without a dongle that I don't have. Same for target disk mode. I'll see if I can find an appropriate dongle locally.

 

[USB3foriMac]

Maybe try a Linux boot stick, or Internet recovery. At least that should give you something o to the screen if it is related to a messed-up update.

 

[Fishrrman]

Have you tried the following?

Unplug it from the wall.
TAKE OUT the RAM (yes, I know it's a pain).
Let it sit that way for about 15 minutes.
Re-install the RAM DIMMs.
Plug it back into the outlet and try to power-on again.

 

[glenthompson]

Took out all the RAM and put back just the original 8gb, leaving out the 32gb OWC Simms. Booted up and it was running the update. Took some time. Restarted fine and seems to be doing ok. I’m going to let it run for awhile then put the OWC ram back in and see what happens. Thanks for all the suggestions.

 

[glenthompson]

Stranger and stranger. Put the OWC ram back in and it wouldn't boot. Took out the Apple RAM and put the OWC ram in its slots and it bots fine. It also seems faster on boot. For some reason it seems the Apple and OWC modules aren't playing well together. Since 32 beats 8, I'll leave the OWC in and see how it does.

 

[sdz]

OWC is a **** company. I had so many problems with their SSDs and RAM. Pure junk.
Horrible products.

I buy now normal brands (non mac related) and never had problems.

 

[Nguyen Duc Hieu]

Stranger and stranger. Put the OWC ram back in and it wouldn't boot. Took out the Apple RAM and put the OWC ram in its slots and it bots fine. It also seems faster on boot. For some reason it seems the Apple and OWC modules aren't playing well together. Since 32 beats 8, I'll leave the OWC in and see how it does.

1. Incompatibility between iMac original RAM and aftermarket RAM is a common problem and has been discussed in this forum for quite a time. Just ditch the original RAM and use the aftermarket RAM. Case closed.

2. NVRAM reset only works if you power the iMac on and it runs to some extends, like the fans are spinning etc. Sometime the iMac appear to be dead and nothing move when you push the power button. My 2010 iMac felt into this situation twice and in such cases, I had to remove everything I could (the LCD, all SATA drive, SD card, the GPU, etc) before it is willing to boot and get the NVRAM reset.

 

[Fishrrman]

OP wrote:
"Took out the Apple RAM and put the OWC ram in its slots and it bots fine. It also seems faster on boot. For some reason it seems the Apple and OWC modules aren't playing well together. Since 32 beats 8, I'll leave the OWC in and see how it does."

I'd say that THIS is "your solution".
32gb that boots reliably beats 40gb that will not.

I'd put the factory-installed 8gb "in a safe place" if you ever need to use it again...

 

[nambuccaheadsau]

Long history of Apple sourced modules not playing nice with after sales memory. Do as the fisho says, run the OWC memory and keep the original modules when it is time to sell. Hav e always found OWC very reliable. Read this from ifixit on this problem:-

SOLVED: iMac won't boot after RAM upgrade - iMac 27" 2017

Ensure you have seated all RAM sticks properly in their slot, verified the keying matches and visually inspected the metal contacts between the RAM and the motherboard. There should no play in the installed RAM. This generally takes more force than is usually expected. Your system's symptom...

www.ifixit.com