820-01041 Has image no backlight

[grmacs]

I can see image on original screen and test screen but no backlight. EDP_BKLT is present. No signs of liquid damage or corrosion.

Below are the Q8400 and U8400 voltages.

Q8400:
pin 3: 12.6V
pin 4: 13.1V
pin 1,2,5,6: <2V

U8400:
pin 1,2: 0.3V
pin 4: 0.0V
pin 5: 5.1V
pin 9,10: 13.1V
pin 11: 12.4V
pin 12: 0.0V
pin 15,16: 4.5V
pin 17: 3.3V
pin 18: 5.1V
pin 19: 0.2V
pin 21: 0.0V

Could this be a T2 issue needing revive/restore? Seems nowadays all roads lead to T2

 

[2informaticos]

Check R8450-53 and their traces.
Also check voltage and diode mode on SCL/SDA lines.

 

[grmacs]

diode of pin 1 for R8451/0 are both .515 voltage is 4.5V at both as well. Traces all good.

 

[2informaticos]

Be sure D8410 is not shorted A-K.
Check diode mode to ground on both sides.

You may need to change U8400.

 

[grmacs]

Man, I don't know how but I thought I had checked PPVOUT_S0_LCDBKLT for short already. Sorry for wasting your time! There was a short on on C8462. Guess I'm just over here making things harder than they should be.
Thanks for helping me pull my head out of my ass haaha