820-3437 no voltage on PPVIN_S0SW_LCDBKLT_FET

nate8organic

New member
Repaired this board liquid damaged. sold on ebay to a repair shop, buyer claimed the board would not power on for 3 min or something like that. got it back and the shop was using the customers computer for its testing they included a fan that was broken so hence why he thought it would not boot. and he killed the the video output by obviously using the customers screen. so now i'm trying to fix this. i get no power on legs 1 2 5 6 on the q7706. 8.56v on pin 4 and 8.3v on pin 3. check ohms on r7788, r7789, Replaced q7707, and q7706, with no changes. any ideas?
Thanks
Nate
 

nate8organic

New member
Update i just noticed that i did not put the right reading... pin 5 is 0v and pin 2 is 0v. u2071 i have 3v on pin 5 but 0v on pin 1, would you suspect the u2071 to be dead(i need to look and see how 3vs0 gets to pin 1 if it comes from pin 5 or from the other side of the board)? also pin 2 and 3 are also 0v on the u2071. r1430 is 0v and that goes to the cpu. could he have fried the cpu?
 

nate8organic

New member
Okay your def right about that! i have 3.32v on pin 1 not sure how i miss read that. I did check smc_lid it is 3.32v.
i do not have anything on pin 4 and 2 still though
 

dukefawks

Administrator
Pffff, the LCD is not recognized. Check all caps and resistors in the DP lines C8320 and friends. Inspect connector for damage.
Of course there will never be backlight if you don't even have an image.
 
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