820-00165 Small water damage around L7701. No backlight.

[MaxFix]

Hi there,

Feedback line was missing because the pad was totally destroyed by corrosion (see the picture).
Ran a jumper to another pad (see picture 2).
Replaced the backlight driver IC.
Still no backlight. 8.5V on the coil.
Checked BKL_PWM - was low (0.8V). Connected C7711 to pin 2 instead of R7704.
BKL_EN is 2.7V
Still 8.5V on the coil and strange backlight on the screen: I dont see folder but rather a whole screen goes solid dark color.

Please help. Thank you.

 

[2informaticos]

I don't understand where did you run the wire.
It doesn't look to go as the red line marks.

When PWM is low, do PRAM 3 times first.
If still low, remove R7704 and run wire from C7704 to R7715.

Post diode mode to ground on all return resistors, R7717-22.

 

[MaxFix]

Found the problem. Diode was soldered other way around by someone who tried to fix this board previously. Thanks for your help!