2015 iMac Won't Start after SSD upgrade

[gershbec1]

A week ago I upgraded the hard drive on my 2015 21.5" iMac running Catalina to an SSD drive. Worked great for a day after which I couldn't start up my computer due to some type of error (detected in Disk Utility) with the formatting of the drive. I did some research and it was recommended that I reformat the drive and reinstall the OS. Done.

After this, my computer had been running well for the last few days. I ran Disk Utility on it yesterday to make sure that the error hadn't reappeared and everything looked great. Today I sat down at my computer and the Recovery Mode screen was on my computer, listing the 4 options (Restore From Time Machine, etc.). Apparently my machine had crashed and had somehow entered this mode.

I quit out of Recovery Mode and restarted my computer. Now the computer turns on but I am only getting a black screen, with no chime. I can't enter Recovery Mode, Diagnostic Mode, Internet Recovery Mode, startup from USB, etc. I've done all the basic troubleshooting that I can but I've run out of ideas about what to troubleshoot.

I'm at the point where I'd bring it to a Genius Bar and have them tell me I need a new logic board but they're all closed. I also find it a strange coincidence that I would be having logic board or any other type of hardware issues when I have just bought a new SSD, unless somehow the SSD caused these issues. And why was I able to have Recovery Mode appear on my screen before I restarted it? I'm considering reopening the machine just to check all of the connections, though I'll only do that if I have to because them I need to get some new adhesive to get it all back together.

Any ideas on further troubleshooting would be greatly appreciated.

 

[chscag]

Welcome to our forums.

First thing I suggest doing is to try to boot the machine from an external bootable source to see if it will boot up that way. You can use a cloned drive (if you have one) or any USB bootable source. If you have another Mac, you might be able to use Target Disk Mode but the bootable USB source is better.

It is possible that the SSD you installed has failed. There could be other reasons but that would be my first suspicion.

Let us know.

 

[gershbec1]

I’ve tried it with a bootable usb but holding down option (or any keyboard commands) on startup doesn’t bring anything up. Just a black screen. Will take a look at if target mode is an option.

 

[ferrarr]

Have you tried safe mode to boot your Mac?

How to use safe mode on your Mac - Apple Support

 

[chscag]

I’ve tried it with a bootable usb but holding down option (or any keyboard commands) on startup doesn’t bring anything up. Just a black screen. Will take a look at if target mode is an option.

I just noticed you mentioned that you do not get the POST chime and the screen remains black. That's usually indicative of a hardware problem of some sort. Not being able to boot from a USB source also says the same thing. I doubt target mode will work but you can certainly try it.

You probably should open the machine again to see if you can notice anything out of the ordinary. Your machine does not have a separate graphics card but rather integrated with the CPU so can probably rule that out as a failure.

Although Apple Stores are closed, AASPs (Apple Authorized Service Providers) remain open for the most part. Since your machine is no longer under warranty, it really doesn't matter except to say that a AASP will charge for diagnosis whereas an Apple Store genius bar will not.

Also you didn't mention whether your machine was a 4K Retina or the standard version.

 

[gershbec1]

Standard version, not retina.

Incidentally, after sitting there with a black screen for an hour, eventually the folder with a question mark icon popped up. Not sure why it took so long but that seems to imply that it’s a problem with the drive. I’m having OWC send me a new one.

I’m not sure why a hardware issue would suddenly appear after upgrading the SSD unless it was somehow initiated by the upgrade (or it’s a coincidence). But my initial thought was dead logic board, particularly since I’ve had multiple iMacs with the same issue.

 

[harryb2448]

How did you donthe clean install on the SSD? Did you make a bootable installer on an +8GB thumb drive? Formatting APFS and GUID partition?

 

[gershbec1]

Clean install with a bootable usb. The second time I installed (after the first failure) was from recovery. APFS with GUID both times.

 

[Lifeisabeach]

What model SSD did you get? You said OWC was sending you a new one. I've long used OWC's SSDs but in the past year or so developed issues with their drives on two different Macs. I can tell you that a 2010 iMac my in-laws have from me that is stuck on High Sierra is still using an OWC drive just fine. But 2 newer Macs in my household started having issues with Mojave, both of which also had OWC SSDs for some time and had been problem-free beforehand.

I'm not sure if I was unusually unlucky, but many of OWC's SSDs use the SandForce controller and that is frowned on in some circles. It's possible that Mojave and onwards is simply incompatible with drives using those controllers. I don't have a good answer here, and this is pure speculation right now, but it's something to consider as part of your troubleshooting.

 

[gershbec1]

Hm, that's a little disconcerting. I ordered a 1.0TB OWC Mercury Electra 6G SSD. 3 year warranty but hopefully this new one does the trick.

 

[Lifeisabeach]

Hm, that's a little disconcerting. I ordered a 1.0TB OWC Mercury Electra 6G SSD. 3 year warranty but hopefully this new one does the trick.

Yep, that's the one that was in my wife's Mac mini. It started randomly freezing up and rebooting would give me a flashing ? mark. It'd take 2-3 power downs and restarts before it would work again. Replacing it with a WD SSD restored it back to normal operation. It took me some time to connect the dots because it was seemingly random, but it all started some time after installing Mojave. I had the same issues on a MacBook Air with a replacement OWC SSD in it and didn't make the connection to it being the SSD until I had already replaced the MBA with a new one. Putting the original SSD in the old MBA restored it back to normal operation also.

 

[gershbec1]

It looks like the SSD drive was screwed up. I got a new one from OWC and everything has been stable for 24 hours (knock on wood). My Time Machine drive is not working (other than restoring) but that's probably another issue...

 

[gershbec1]

One more follow up for the public record. Hopefully the last!

My second OWC SSD went bad after a few days. I called them up and they had no idea why. They had me return both SSDs and said they'd look at them - try to mount them, see if they came from a bad batch. Two weeks went by and I hadn't heard from them so I bought a Crucial 1TB SSD. So far no problems. Installed easily, no restarts, no crashes. So perhaps the OWC SSD was the issue. I'm almost afraid to post this because I don't want to jinx it! But a week in and everything is great.

I'm a little surprised I haven't heard back from them since you'd think they'd want to know what the issue is. As someone pointed out, there seems to be some type of potential issue with their SSDs and Apple, so consider yourself forewarned.

 

[Lifeisabeach]

One more follow up for the public record. Hopefully the last!

My second OWC SSD went bad after a few days. I called them up and they had no idea why. They had me return both SSDs and said they'd look at them - try to mount them, see if they came from a bad batch. Two weeks went by and I hadn't heard from them so I bought a Crucial 1TB SSD. So far no problems. Installed easily, no restarts, no crashes. So perhaps the OWC SSD was the issue. I'm almost afraid to post this because I don't want to jinx it! But a week in and everything is great.

I'm a little surprised I haven't heard back from them since you'd think they'd want to know what the issue is. As someone pointed out, there seems to be some type of potential issue with their SSDs and Apple, so consider yourself forewarned.

Thanks for the update. That’s disappointing that OWC hasn’t gotten back to you. Hopefully a refund at least is coming. I wish there was more data to back this, but this “seemingly” would support my suspicions that Mojave and Catalina don’t like these particular drives. If so, OWC needs to own this and either stop selling them or at least post huge disclaimers.

 

[chscag]

I wish there was more data to back this, but this “seemingly” would support my suspicions that Mojave and Catalina don’t like these particular drives. If so, OWC needs to own this and either stop selling them or at least post huge disclaimers.

Seems like those drives sold by OWC do not like being formatted to APFS since that's the default format for both Mojave and Catalina.

 

[Lifeisabeach]

Seems like those drives sold by OWC do not like being formatted to APFS since that's the default format for both Mojave and Catalina.

Well I have one of those in a 2010 iMac running High Sierra and I’m fairly certain it’s formatted in APFS, but that iMac isn’t having issues. It’s my old 21.5” one that my in-laws have now but I can’t check to be sure anytime soon. Actually that has the Mercury Electra 3G model SSD, so maybe the problem is more specific to the 6G?

 

[hoody]

Looks like I dodged a bullet when I installed a Crucial 1TB SSD in my old 2012/13 21.5" imac. I'm usually the unlucky one so I'll have a whiskey or three tonight.