820-02100 no backlight

[kjchatman1]

after inspecting the mainboard i see no liquid damage. i did find the lid angle sensor corroded but still no backlight after detaching it but the keyboard started working again 12v on ppvout_luxe_xw. i can see an image on the screen though

 

[2informaticos]

Did you test with known good screen?

 

[kjchatman1]

i don't have a spare screen but aren't up800 booster chips the common failure point?

 

[2informaticos]

12V on backlight output may be caused by bad UP800.
But other adjacent components may impede it, or QP800-3 to boost up the voltage.