820-00045 a1534 wont turn on at all, not water damaged

[ielectron]

resistance on L7560 455 ohm
double checked PM_SLP_S5_L = 0V
I checked on TP first but looks like board view is a bit different than the actual main board and test point wasn't for this signal

 

[2informaticos]

"PM_PWRBTN_L = 1.22v"
It has strong pull up resistor (1K) to 3V3_S5.
Remove R1405 and check its level again.

 

[ielectron]

resistor removed still no changes on PM_PWRBTN_L
3V3_S5 is still on 0.5v level no changes

 

[2informaticos]

Still 1.22V at PM_PWRBTN_L?
Looks like PCH issue; it should have a weak pull-up resistor inside.

Do you get AVREF_SMC voltage?

 

[ielectron]

yes PM_PWRBTN_L have no changes I checked once more
AVREF_SMC = 3v

 

[2informaticos]

Put good flux and heat PCH untill 180-200 degrees; just to burn eventualy crap...

 

[ielectron]

PCH heated up no changes, I checked those
PM_PWRBTN_L
3V3_S5
no changes on those lines after heating up too

 

[2informaticos]

There should be PCH/CPU, or U7400 problem...

 

[ielectron]

I will try swap from donor board U 7400

 

[ielectron]

U7400 replaced no changes after this too looks like PCH is faulty I'd say