820-3435 occasionally restarts by itself

[KC Micro Tronix]

Since you are dealing with liquid damage there is probably some pad eaten under a component such as a resistor or a IC. This one will be a hard one due to the intermittent nature of the problem. I recommend removal of the board and crawling over it with a microscope and a probe checking to see if resistors and parts in the damaged areas are securely attached. Also chips that have water damage on them I would pull to inspect pads.

 

[2informaticos]

Maybe need to reball SMC.

You can also heat CPU with good flux; just burn eventually crap accumulated underneath.
Finish with ultrasonic cleaner; be carefull, if no sweep option available.

 

[MOMOH]

Thank you so much guys ,

 

[MOMOH]

the issue was the Trackpad, thank you so much guys .