1 My 16” MacBook Pro 2021 M1 Max turns off the screen after 8 seconds
At first it was intermittent black screens. The backlight and keyboard always stays on, and the screen always returns functional after opening and closing the lid. I also confirmed with HDMI output to another screen that the laptop itself does not go to sleep or standby. It will simply stop showing anything on screen. Sometimes when in a dark room, I can see some white washed out elements on the screen moving, especially my mouse. Any ideas on how to isolate this are appreciated. I do have access to specialised measuring equipment.
What can this be? When they tested it in the Apple Store they could not find any errors with the diagnostics. I am leaning towards a hardware problem. Does anyone know of such a system that cuts the video signal after 8 seconds?
I am thinking it could be a failing component on the logic board for power delivery or something similar. I honestly cannot pay the ridiculous fee Apple came up to fix this. They are also not entirely sure that a new screen fixes this.
I am a former PC repair technician and I am about willing to try anything (complex) to make it work again. Can someone point me in the right direction?
Is this a good question?
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What happens when you plug in an external display and try running the system in Clamshell Mode?
by Dan
It works in clamshell mode. So it must be something in logic board component, display itself or maybe flexcable. But I need to diagnose and isolate this further.
by Nikola Brasnik
@nikolabrasnik most likely that would be a LCD-TCON problem inside of the screen. white shadows you see is a backlight, which means display is still recognized, image is still rendered and tcon is controlling backlight led matrix but LCD(decoders + glass itself) is for some reason not powered anymore. one of possible things to check is to remove plastic cover on the lower part of the screen to see if there was some liquid damage to the screen edge. Mac screens seem to have some sort of "integrity" check which disables image if edge is cracked.
by RipperDoc
@inwerp - FYI: The chin plate (under the display) is a thin glass plate not plastic. If you’re not careful it can snap and digging in around the edges could make things worse if the display was still good.
by Dan
@inwerp I’ve already carefully removed the bezel and cannot find any evidence of liquid damage, but I bought the machine as refurbished so one can never truly know. Your suggestion is helpful though. Do you know anything more about this integrity check? I am wondering what exactly you mean by “which disables image if edge is cracked” - what edge are you referring too? Thanks again for the help
by Nikola Brasnik
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