2010 27" iMac steadfastly refuses to take an OS

[SenileOtaku]

For the past couple of months (maybe since February) I've been trying to get an OS to install on a used 2010 iMac (27"). Regardless of how may different USB drives I've tried, how many versions of MacOS (other than 10.9, which us useless at this point), and even Fedora 39 & 40, it will hang at somewhere between 20-80% of the way through, crash/shut off before it's done, or never even run the boot at all. Right now I have an OCLP Ventura install USB I created, and it's stuck right at the beginning of the boot (sitting there for 20 minutes doing NOTHING). Exactly what happened with the previous copy I made of that installer in another USB drive (yes, even tried an SSD rather than a flash drive). At most had an install of Linux Mint LMDE6 which managed to run for 3 hours before completely locking up, after which it wouldn't run more than 5 minutes

I've changed the HDD (to a new PNY CS900 SSD), changed the memory, cleaned out the inside and replaced the thermal paste, etc). I don''t have other Mac parts to swap into it, and I'm not going to just start throwing iMac-specific parts at it thinking something might stick (whatever I've bought thus far can be used elsewhere)

So what is the next step with this p.o.s? Right now smashing it to bits with a sledgehammer os sounding better and better. At one time I would have just brought it to the range and put a clip of .223 through it.

 

[casperes1996]

Have you tried running the Apple Hardware Test?

 

[throAU]

Get an offline installer
set the hardware clock/date to 2015
try again

 

[casperes1996]

Get an offline installer
set the hardware clock/date to 2015
try again

Generally good recommendation but given it also fails on Linux, I doubt it’ll work. But good advice in general and worth a shot

 

[throAU]

Yeah I missed that, but I've been bitten by the code signing vs. date before.

As you say, there's every chance the 14 year old hardware is dead/dying in some way. Quite likely (but not necessarily 100%) dodgy RAM.

Given the RAM was just changed, it's possible that it's not entirely compatible or faulty. Or one of th modules isn't seated properly.

I'd run Apple Hardware Test to see if the RAM is OK, if it runs into errors remove one of the sticks and try the test again. If that still fails swap the stick with the other one and try again.

Once the RAM is confirmed known-good try the OS installer again.


It could also simply be failing/failed capacitors in the machine or power supply somewhere. basically with 10+ year old hardware, things like capacitors eventually wear out and hardware diagnostics/repair can be a crapshoot.

 

[casperes1996]

Yeah I missed that, but I've been bitten by the code signing vs. date before.

I had to learn about it the hard and confused way myself. Twice in fact as I forgot and had to learn again once

 

[Nguyen Duc Hieu]

For the past couple of months (maybe since February) I've been trying to get an OS to install on a used 2010 iMac (27"). Regardless of how may different USB drives I've tried, how many versions of MacOS (other than 10.9, which us useless at this point), and even Fedora 39 & 40, it will hang at somewhere between 20-80% of the way through, crash/shut off before it's done, or never even run the boot at all. Right now I have an OCLP Ventura install USB I created, and it's stuck right at the beginning of the boot (sitting there for 20 minutes doing NOTHING). Exactly what happened with the previous copy I made of that installer in another USB drive (yes, even tried an SSD rather than a flash drive). At most had an install of Linux Mint LMDE6 which managed to run for 3 hours before completely locking up, after which it wouldn't run more than 5 minutes

I've changed the HDD (to a new PNY CS900 SSD), changed the memory, cleaned out the inside and replaced the thermal paste, etc). I don''t have other Mac parts to swap into it, and I'm not going to just start throwing iMac-specific parts at it thinking something might stick (whatever I've bought thus far can be used elsewhere)

So what is the next step with this p.o.s? Right now smashing it to bits with a sledgehammer os sounding better and better. At one time I would have just brought it to the range and put a clip of .223 through it.

You can't solve a hardware problem with a software only solution.
On a beautiful day, my iMac 2009 showed exactly the same issue you describe: Boot Mac OS High Sierra to 70~80% the progression bar then hang there forever.
But I didn't get panic and try many other versions of Mac OS. As I know for sure the graphic card had failed.
Replacing the graphic card solved the problem immediately: High Sierra was up and running, after an OCLP patch for the FirePro M6100m I'd just installed.

For your case, I suggest you pull the graphic card out and reflow the GPU chip, it may help or not with the display issue, but it will solve your hanging problem.
How to prove: Boot the GPU-less iMac with a Linus distro and try SSH to it from another computer=> If you can SSH, then the issue is definitely the failing GPU.

 

[SenileOtaku]

Have you tried running the Apple Hardware Test?

Diagnostics (either with "D" at power-on or <option>-D) tries to connect to the internet server then fails with a "-6002D"

I have tried editing the nvram setting for the install server (to use http rather than https) but I had to use the example from MrMacintosh's site since I never get to a point where I can even bring up the terminal window to see what the system currently thinks it should use. (probably time to reset nvram again to start from scratch).

 

[SenileOtaku]

You can't solve a hardware problem with a software only solution.
On a beautiful day, my iMac 2009 showed exactly the same issue you describe: Boot Mac OS High Sierra to 70~80% the progression bar then hang there forever.
But I didn't get panic and try many other versions of Mac OS. As I know for sure the graphic card had failed.
Replacing the graphic card solved the problem immediately: High Sierra was up and running, after an OCLP patch for the FirePro M6100m I'd just installed.

For your case, I suggest you pull the graphic card out and reflow the GPU chip, it may help or not with the display issue, but it will solve your hanging problem.
How to prove: Boot the GPU-less iMac with a Linus distro and try SSH to it from another computer=> If you can SSH, then the issue is definitely the failing GPU.

Trying different versions was to see if I had bad copies, or to see if somehow I couldn't create a USB that it would work with (thus why trying Fedora, as I can readily create known working installers, including burning to DVD).

But the GPU verification test is precisely the sort of test I need. Because right how I could see three parts that could be bad; the mainboard, the GPU, or the power supply. I did a visual inspection of the PSU and didn't see any visibly bad caps, but I'd still have to try testing the power rails (something I haven't done before, although have watched Louis Rossmann, Adrian Black, etc do the same thing). Pulling the mainboard will be a lot more involved (I already did that to replace the thermal paste & clean the cooler fins, not the worst system I've worked on).

 

[SenileOtaku]

The 2015 date change got the system to install an OS (with the GPU and display still attached). Tried to set up a benchmark/stress test but the system locled up before I could start it.

So trying the Linux headless install with the GPU removed worked once for installing Fedora 40 Server (having a kickstart file to redirect to VNC). But it either didn't install/enable sshd, or simply didn't want to accept connections for some other reason (checked the IP address in OpenWRT, so I know that was correct). Any subsequent attempots to install using a kickstart that properly enables everything, nope (even asking the Fedora people at work on how to tweak kickstart didn't resolve it).

I *could* just try the reflow anyway, it's pretty much unworkable anyway, can't break it much further. There's always still the sledgehammer option (on the internal boards, I'd turn the display panel into a monitor for my regular computers). Could use a way to vent frustration after a day at work.

Had hoped to get this working before my daughter comes home after graduation, this one has more memory, a better display and better processor than the underpowered Dell the in-laws handed down.