820-3115-b powers up, starts loading os, then cuts power completely.

[drewrox2009]

This board did have liquid contact. Plenty of corrosion along the hinge edge of the board.

replaced q5480 and repaired a trace between. pin 4 and pin 1 of r5481

also repaired trace between r3896 and c3888

replaced f9700.

Not sure where to look.

Hoping it isn't an smc issue

probelm happens with/without battery

with without bil

 

[aprendiz]

Check if on SMC by pass still shuts down.....
Also try another ram memory, try one slot at a time...

 

[drewrox2009]

Great idea i didn't even think about smc bypass.

 

[TCRScircuit]

Check Current Sense resistors in u7000 area

 

[dukefawks]

Disconnect keyboard to rule out a flaky power button. Corrosion under SMC also very likely.

 

[drewrox2009]

Does the same thing with smc bypass, however after it crashed i unplugged and plugged back in and am presented with an efi password for the first time, Is it possible i have a corrupt efi? The customer did provide the proper password and it does accept it however it still crashes the same.

 

[drewrox2009]

and more interestingly, with option held at boot it will crash before the boot menu.

 

[dukefawks]

I said to disconnect keyboard. Reflow SMC and inspect for corroded reistors.

 

[drewrox2009]

Did test without keyboard connected. Did reflow the smc after removing underfill. Did replace any corroded resistors i could find. Too much time invested into that board, sold customer a replacement board.