MacBook Pro 16 2021 820-02100

[2informaticos]

Check if RP803/9 have still correct ohm values.

No voltage at all at PPVOUT_LUXE?

BTW, all voltage checkings on backlight circuitry MUST be done with LCD connected!

 

[isa1985]

I found the problem. QP800 actually looked fine, but when I inspected it under a microscope from the side, I saw that it was blown. I removed the QP800 from an 820-02020 board. According to the datasheet, they seem quite similar, but I would kindly ask you to verify this. Although they are different models, both are N-channel MOSFETs. In any case, the backlight is working now, and everything is functioning wonderfully.