820-3437 a no backlight

[zockysworkshop]

On Q7706 in pin 3 and 4 i have the same voltage so Q7706 doesn't open i checked the voltage divider the R7788 and R7789 are good but anyway i replace them and still im getting same voltage on 3 and 4 looks like the divider is not lowering the voltage. Any ides ?

 

[dukefawks]

EDP_BKLT_EN is missing I bet. Do you even have an image? Is SMC_LID high?

 

[zockysworkshop]

Yes EDP_BKLT_EN is missing its hard to see if there is an image when i plug usb dongle is not lighting up i have PPVCC_S0_CPU and the SMC_LID is 3.4V

 

[dukefawks]

Uhm, you mean the board is just brain dead? USB mouse not lighting up?

 

[zockysworkshop]

So this board was water damage around U7501 so i replaced the chip and there was damaged via's that i jumped wires and the computer turned on i boot it to OS but i had so much flux on the board so i wash it in the ultrasonic cleaner again and it didn't gave me backlight after or image not sure. I do proper ultrasonic cleaning if you want to ask that with CREST and proper Branson solution and dry the board next go to alchohol and in oven for 10 min on 200 degrees celsius.

 

[zockysworkshop]

Look like brain dead but i'm not sure

 

[dukefawks]

200C for drying a board?? That will melt all your repairs with normal solder! 120C is more than enough.
No idea what happened now, inspect for corrosion or damaged components.

Plug in a USB mouse and see if it lights up, if not it is brain dead.

 

[zockysworkshop]

sorry it Fahrenheit lol. Yes no light on USB

 

[dukefawks]

Well, there must be corrosion somewhere else too. The usual spots, U6100/resistors, clock chip, under SMC