820-00165 no display

[arnonabuurs]

Hi, have this Mac air, had a tiny drop of corrosion on C7137 but board looks very clean, replaced that capacitor. Mac starts spinning, turns off, then keeps spinning. I have all voltages going down to DDR 1.2v and CPU 1.05 and 1.8v, on display voltage only get 6v and then starts to drop, I have no PP3V3_S0SW_LCD_R and no EDP_PANEL_PWR but I do have 3.3v S5 on VIN at U8300. Mouse lights up. Ideas? I have tried another working LCD, same.

 

[2informaticos]

It has eDP display, so needs 3V at pins 18/19 of J8330 at least in the first 1-2s; even w/o LCD.
In that time DP_INT_HPD must go high; when LCD connected, of course.
If not, LCD cannot be recognized by PCH.
If DP_INT_HPD drops, or doesn't come high at all, EDP_PANEL_PWR will disappear too.

 

[arnonabuurs]

I get nothing when turning on on these pins. Could be a CPU issue? I also read somewhere that flashing the rom fixed the issue?

 

[2informaticos]

You can try to reflash BIOS, nothing to lose; make backup first.
Can you confirm USB activity for sure?

 

[JohnB8812]

Dead CPU most likely the on off on is no bueno on 00164/5. Try BIOS first tho to rule that out.

 

[Ciki]

did u fix it .have same issue