820-00244 Boots, slows to a halt, freezes and doesn't boot successfully for ~2/3 hours

[macdude101]

Got an 820-00244 in that the customer explained boots to the login screen, or occasionally to the prohibitory symbol, but then very quickly slows down until it freezes and stops responding. Customer mentioned getting the "the computer restarted because of a problem" alert if they're able to log in quick enough. Once it's unresponsive the caps lock key no longer illuminates and there's no USB activity if an optical mouse is connected.

At this point if it's rebooted, it draws power, the trackpad becomes clickable but nothing further occurs (no logo/chime, no USB activity, caps lock light or external display output).

If left powered off and connected to power for ~2/3 hours it will then boot successfully again and the cycle repeats.

Board looks clean, no signs of liquid damage. Originally thought this was going to be another bad CPU but symptoms seem a little different from what I've seen before.

 

[macdude101]

Upon further testing its looks like the amount of the it needs to 'recover' and boot successfully is related to how long it was left powered 'on' before.

Wondering if this perhaps could be a sensor issue.

 

[2informaticos]

Bad CPU, like all these bullshit boards...
It can revive with reflow, but that is not a serious solution.

 

[macdude101]

Disconnecting the top case seems to have resolved the issue with it not booting consistently.

Reach the FileVault login screen however there are graphical glitches (as attached).

Logging in kernel panics. Recovery mode kernel panics. Internet recovery mode kernel panics. Booting from an external drive kernel panics. Very consistent.

 

[macdude101]

Got further with verbose mode, looks like an incomplete macOS installation.

It began installation process again, ETA 24 mins, after ~30 seconds logs appeared on-screen noting launchd assertion failure and all processes would be killed.

Rebooted to Apple logo & progress bar, reached end of progress bar and rebooted/shutdown, unable to boot subsequently.

No USB activity, does not respond to power input, base of laptop warm.

Back to square one. Seems like this might be a combination of a software & hardware issue (maybe the former caused by the latter).

 

[2informaticos]

Software and internal SSD easy to discard.
Boot USB macOS.
Try to recover any data, if you get logged in.

 

[macdude101]

Unable to boot from USB drive. Kernel panics.

Managed to capture a kernel panic whilst in verbose mode though so got some logs:

panic(cpu 2 caller 0x…): Kernel trap at 0x…, type 13=general protection

Wondering if this is perhaps bad RAM.

 

[2informaticos]

More likely CPU.
This board is hopeless.
You can try to reflow the board entirely; do note expect to last...