820-00165 backlight issue

[laptopcity]

Hi ive got an 820-00165 with a backlight issue, the problem is backlight does come on for a sec then goes off , it did have a liquid pill but only very light, ive change led driver just incase and c7796, c7797, c7799 just to be sure , i am getting 8.5v at L7701 so voltage is getting there

 

[2informaticos]

Maybe bad solders at U7701.
So many threads about backlight problems at 00165.
You should already got lot of info about what to check there.

Why don't you post relevant measures on the backlight circuit?

 

[JohnB8812]

Sounds like an SMC_LID problem. Tried new DC-in board/cable? J9500 pins ok?

 

[laptopcity]

thanks to you both, although lio connector looked good, i removed it to find a bad 3v42 trace underneath, fixed the trace and replaced the connector and now green light plus backlight both working , guess thats a lesson learnt and thats fix green light issue first before anything else