820-00840-a

iFix

Member
Hi.

I have this board which is powering on but not showing picture. First i fixed flexgate just to make sure that it will run properly and since it's no picture issue of course no change. The laptop powers on fan spins and then just stays like that and it was not liquid damaged. Some time ago the client went to so called Apple official and they replaced the top case(keyboard housing) complete for no reason besides some keys pressing hard(probably from dust). Any ideas ?

Thanks
 

2informaticos

Administrator
Staff member
Then do not waste time expecting internal video.
Your board doesn't boot at all.
Turned on, is not the same with working board which has some particular problem.


Disconnect trackpad and any other flex, and check again for USB activity.
Do you note any variations on VCORE in the first 10-15s?
 
Last edited:

2informaticos

Administrator
Staff member
"this board which is powering on
--------------------------
PPBUS_G3H is 0v"
I don't really understand; how is that possible???
 

iFix

Member
It was at a power on state probably something went off in the meantime. I'm not trying to take your time so please don't try to make fun out of what i wrote. I understand that you encounter many different ppl on the forum, but i really appreciate the support and would appreciate even more a bit more professional response. Thank you very much as always and once i fins time to measure all voltage i'll write back.

Have a good day
 

iFix

Member
I have replaced U7000 and that made a difference i got 20v on D6905 PPVIN_G3H_P3V3G3H but then U6990 burned and i replaced it now also u1900 was overheating and i replaced it also short is removed. Now i'm back at 5v and a short on C3108 and C3208 which came to be a short on U3200. I removed U3200 and now i'm stuck at 5v on the U3100...
 

iFix

Member
Staying on 5v on both ports after replacement of CD no short anywhere. Maybe i need to update firmware?
 

iFix

Member
Just got back to this board. 1V1 LDO no voltage. Also replaced u7000 again cause with he old one i was not even getting 5v on it
 

iFix

Member
Would it make a difference if i don't have C3208 on the board cause it was shorted i had to remove it...
 
Top