Early 2008 iMac Doesn't Boot, Where to Look Next

derpimpkar

macrumors newbie
Original poster
May 1, 2017
2
0
I picked up an early 2008 iMac 24" that isn't booting. As I'm learning how to troubleshoot these things, I've reached a blockage and I'm looking for next step suggestions.

iMac:
Early 2008 24", EMC 2211, El Capitan

Issue:
The iMac attempts to boot and stops about 1/2 the way through the progress bar on the Apple logo screen. Sometimes the exact position changes slightly but it's typically 1/2 the way through.

I took the hard drive out and used my working iMac to install El Capitan on it. I verified it boots to El Capitan and was able to create the initial user successfully. I reinstalled the hard drive.

Things I've Tried:
Single User Boot: Successful
Safe Boot: Unsuccessful, however progress bar goes approximately 2/3 the way through.
USB Boot: Unsuccessful, however progress bar goes approximately 3/4 the way through.
DVD Boot: Unsuccessful, however progress bar goes approximately 3/4 the way through.
Verbose Boot: Unsuccessful, it looks like the log is asynchronous so the order of the message varies slightly but these are typically the last messages -
- disk1s2: alignment error
- en1: channel changed to 1
- AppleLPC::notifyPlatformASPM - registering with plugin with ASPM Support true
or
AppleLPC::notifyPlatformASPM - registering with plugin with ASPMGot incomplete channel sequence length 0, should be 16
- There are two RAM sticks. I took each one out individually to see if it would boot but it's the same case with either one or both. I don't have known good RAM for this system.
- I've attempted to use diagnostics but pressing "D" when the system starts doesn't seem to do anything. The system will end up in the issue state above.

Next Steps:
I think it's a hardware issue at this point. My guess is the logic board or the video board. Forum searches point this way but I haven't seen many with a certain resolution. However, I'm not sure and I don't want to start spending money to rule out parts. Does anyone have suggested next steps?

Thanks in advance,
Tom
 

derpimpkar

macrumors newbie
Original poster
May 1, 2017
2
0
Thank you for the suggestions.

The "/sbin/fsck -fy" command ended with "The volume OSX appears to be OK" so no luck there.

I also tried the PRAM reset just to rule it out if nothing else. Also no luck.

I'm going to make the boot USB with the AHT binaries and see what I get there. It sounds promising.

Tom