[SOLVED]820-3115 works now but all kinds of sensing circuit issues

[roy.ruan]

had a 820-3115 A1278 came in, clean board, no liquid spilled, had no power.

traced down to the SMC,then replaced it

machine powers on, boots, everything working. except sometimes it slows down, then ran ASD. got

VC0C,VN0C,VP0R, ID0R,IC0R,IHDC,IM0C,IO0R,IPBR,

all say the same thing : sensor reading above alarm limit.

pole around in diode mode around these signals into SMC, no short to ground.

so thought can be a bad SMC, replaced another one, same story,power up with these errors, any thoughts?

 

[larossmann]

What voltage do you get on pin 8 of U5010?

 

[roy.ruan]

3.3 something

 

[dukefawks]

Looks like SMC is missing AVREF which is needed for the A/D converters. Check voltage on C4920.

 

[roy.ruan]

FIXED! thanks a lot! turned out to be bad trace to the pad of the SMC, jumped a wire and all good now running without errors!
Thanks a lot guys,appreciate it!