Weird Problem after Modfail Switch Lite

[Harak]

Hello,
i got a Switch lite from a client with a failed Modchip. He removed everything and now i have it on my bench.
checked the usbc meter and it was charging the battery normally, but no screen, no boot
under the microscope i checked all mod points and noticed that the sp1 and sp2 caps are damaged. although it should work without it, i replaced them.
after plugging it in a charger the screen started to flicker. i let it charge over night and the next day i unplug the battery and replug it and it worked. the switch started normally and everything was fine until i press the power button. than it went black and started to flicker again. i never heard of this kind of behaviour before. I late noticed that it freezes randomly too, if you dont press the power button.
i checked everything twice. i really dont know what else i can do. i hope the community can help me. thanks

 

[thesjaakspoiler]

The fact that he brought it to you is because he already wrecked something.

Freezing can be caused by power related issues like something drawing too much current.
Maybe the client messed up the LCD backlight circuit somehow.
It could be as simple as a broken capacitor that causes a spike in the current draw.
If you press the power button, then the Switch goes into standby and turns off the backlight and turns off all kinds of power rails. When pressing it again, it tries turning on the LCD backlight again.

I don't know if this works but you could remove the LCD, put it in the dock and see if it freezes or not.
If it is the backlight driver circuit, then without the LCD it should not have any load on it.
It could also be something on the main power rails that was damaged.

On the following site there is a ton of power related information for an unpatched Switch but the Lite is very similar.
If you can get it in the flickering/faulty mode, then you can measure for irregularities.
https://www.retrosix.wiki/full-boot-from-bench-power
https://www.retrosix.wiki/diagnostics-power-draws-nintendo-switch