820-4924 no backlight

[Jay]

0.857 on R7750, 0.570 on R7751 both sides.

 

[dukefawks]

Pin 4 at .857 is too high, so bad trace or bad U7700.

 

[Jay]

I have continuity from pin 3 all the way to U7700. U7700 was replaced and issue persisted.

 

[jadao]

Problem inside lcd connector?

Are you sure you are probing the 3rd leg of connector not the pad?

If you have a spare lcd cable you can connect it and check again diode mode from R7750 to pin 4 on the other end of cable.

EDIT: I realized and think lcd connector has nothing to do with higher diode mode value...

 

[dukefawks]

I don't know. Only thing I know is that .857 is too high. So probably dead/killed U7700 again.