820-3787 No backlight or image

no liquid damage, board is clean and no signs of corrosion, display comes on external monitor but its no image or backlight on lcd, checked l8300 and lcd_bklit_en_l is 12.40volts, so no voltage is passing it, r7742 is 0 volts, so i removed it and hooked that line to pp3v3_s5 and then backlight started working, but there is no image..can it be u9600, i have already replaced u7701 and u7750.
 
Last edited:
Pram reset done,
pin 9: 0v
pin 28,29,30:5v(even without lcd connected) i have seen in other board that pin 28 goes high for few seconds then it goes low, but this one stays at 5v all the times
 
Last edited:

2informaticos

Administrator
Staff member
Pin 9 should go high.
If not, 28-30 should also drop...
HPD signal comes from LCD, so check another known good assembly from same year.
 
Yeah, tried with 3 good lcds from same, but same result, removed u9600 and its pin 1 is corroded on chip itself, i have a board with same number, can i replace it from there?
 
Top