820-3476 Bootloop (but sometimes turns on)

[arash]

It had Liquid damage all over it.
The Fan spins for 1 sec and stops. Then it starts again, to do the same thing over and over again. Sometimes (Especially if we start it for the first time after a long time) it boots, no problem whatsoever.
We already replaced EFI chip after ultrasonicing it, bot no success.

 

[2informaticos]

See if starts in SMC bypass mode.

 

[arash]

How do i do that ?

 

[2informaticos]

Remove battery, unplug charger, press power button, plug charger and maintain power button pressed 5-10s.
You can use R5115/16 pads instead of power button...

 

[arash]

still doesn't work (Fanspin steady tho)

 

[2informaticos]

"Fanspin steady"
So board stays on in SMC bypass, but not working?
Did you test USB activity?
Check if all big coils get voltage.