Three 820-01700 32GB Logic Boards Same Issue: Won't Wake From Hibernate

[ugamazing]

I have three identical-spec 820-01700 boards (2.6/32/512), and ALL THREE boards came to us with the same fault, from different sources: The boards don't wake from hibernation with the keyboard or lid, they ONLY wake when you press the power button. I understand this is a very minor issue, but the boards must be fixed!

We will of course begin with the obvious (checking lid signals), but I couldn't help but notice these three boards were all 32GB variants. Has anyone noticed an issue relating to these 32GB boards in particular? I of course don't think it's a RAM issue, but it's bizarre that all three boards are the 2.6/32 configuration, a more uncommon one. I've also not seen this issue on any other 820-01700 boards, let alone three with the identical fault!

Has anyone seen and resolved this issue? Based on our tests with the boards (including DFU restores, multiple cases/LCDs tested, inspection for damage/liquid, etc), I'm beginning to suspect either CPU or T2 faults. We won't know more until we begin taking measurements during the failure, but wanted to get this posted in the meantime.

Thank you in advance for any and all assistance or tips!

[ugamazing]

OK, so I found some other peculiarities with these boards: They will all wake up normally ONLY VIA the TouchID button. If you press any other keys or use the trackpad, you can feel the haptic feedback but you get no video or waking of the system. If you hit the TouchID button, boom--instantly comes back from hibernate. So the units are not crashing during sleep.

Also, the boards DO NOT HANG when in safe mode, and they all wake normally on lid-open. Again, these have been tested in 3 different test-cases that we have used for years (I am eliminating the possibility of randomly-failing non-board components).

Has anyone seen this specific issue before? Very odd. I hope it's not the T2 chips on these being faulty; I know the 32GB configuration boards use different chips, so really hoping it's not a bad run of *536 T2 chips.

[ugamazing]

Replaced the GPU on one board and no dice, same behavior. I thought the behavior being fine from safe mode might have indicated a GPU fault, but behavior is completely unchanged after replacing GPU. Suspecting a possible T2 fault.

[mon2]

Not a software problem since it works in safe mode?

[ugamazing]

Thank you for the reply!!

Unfortunately not; we've DFU'd each board probably 5 times, and the issue persists (I suppose it could 'still' be a software issue though?). Boards will wake up if you push the TouchID button, but not with any other keyboard/trackpad/etc movement--but trackpad will click normally. Touchbar doesn't work at all until you hit TouchID button, then units wake up as normal. They all act the *exact* same way, in various different test cases. I'm starting to wonder if they all have a similar type of "damage" from possibly being connected to faulty LCDs or something before we got them? Such a weird failure.

I'm going to swap the T2 from one of the affected boards to another non-affected board and will see if the issue follows the T2 or not.

[mon2]

But..they each wake up normally if operating in SAFE MODE - so the many layers of software are bypassed. That is, perhaps some software or configuration is causing these events? Can you test with another known good installation of the OS?

[ugamazing]

We have only done the DFU restore and reinstall via Internet Restore. We've done a fresh/clean install in all cases. I've not tried to 'downgrade' the boards to check that, but is that what you would recommend? Will there be any issues with booting to a lower-version USB in that case? Haven't ever tried on one of these, but know we'll need to allow booting to external drives to do so.

Would simply booting to another version of MacOS on an external drive be 'enough' to test this possible software issue, or would the BridgeOS need to be 'match' the current OS version to fully test (i.e. the older version of MacOS actually installed onto the board first)? Does that make sense?

Thanks for the recommendation! Will try to get an older version of MacOS loaded for testing.

[mon2]

Yes, try to boot from an external drive. That should be enough.

[ugamazing]

I just booted one of the affected boards to an external drive running Big Sur, and the behavior was identical; I even used a totally different casing assembly, just to be sure.

Once unit is closed for more than a minute or so, it doesn't wake on-lid-open or when hitting any keys or the trackpad (trackpad haptic works, but no touchbar or video/backlight). Board/unit only wakes when you hit the power button.

So bizarre!

[sajidmirza]

Check LID_OPEN_SMC_IN line
R4896
U4802