820-3437- Green light, no fan spin but sometimes boots. VERY temperamental

I have a really odd one. 820-3437 came in with no sign of life except green light. Pulls around 0.018A from DCPS. Sometimes it turns on but most times it's dead.

Used a thermal cam and it was able to detect that the ISL is 1 degree warmer than the rest of the board consistently but that probably doesn't mean much.

Board looks pristine but I do suspect it's been through an ultrasonic before because of the discolouration of the test points and the board has definitely been removed before
 
have just been told that they have used a fake charger and this happened.

I tested something myself, I used a original charger and it 100% doesnt work. when I use my DCPS with a macbook cable, it works 20% of the time but only in a certain direction it seems. Yes have tested new DC in board
 
once I get the issue sorted once it works indefinitely even after shutting down. I have scraped the contact points around ISL earlier. Before I did that the machine showed no sign of life. now it's booting properly once I get it going. I have noticed that regardless of a real and fake charger, if I plug it in, the first time it will never work. but if i do it a second time it always works. It's only an issue when the battery has been disconnected before. Is this just a quirk with this particular machine? Like i said it was dead before I started messing around ISL.

I would just like to know what exactly happened
 

2informaticos

Administrator
Staff member
First, check resistance between pins 17/18 and 27/28.
The issue looks like leakage and original detects it and stop to power the board.
Check around Q7010, R/D7012...
Post exact values of R7180/81 and R7185/86, measured onboard.
Possibly Q7180 need to be changed.
 
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