820-00923 20v 0.00amp no power

[Soji]

it’s a water damaged system, no deep corrosion on board.
Almost all voltages are present except
PP5v_s4

 

[2informaticos]

Pretty sure almost NO.
Many secondary voltages are 5V_S4 dependant!

PM_SLP_S4_L pulsing if you trigger SMC_ONOFF_L?

 

[Soji]

I triggered SMC_ONOFF_L by shorting it to ground, nothing happen,PM_SLP_S4_L still 0.00v

 

[2informaticos]

"shorting it to ground"
Just temporary contact, don't keep it tied to ground.
And check for pulse at same time.

 

[Soji]

That’s what I did exactly. It’s 0.00

 

[2informaticos]

Do you note a drop pulse at PM_PWRBTN_L, at same time?

 

[Soji]

I must use oscilloscope? Can I use voltage on a multimeter

 

[2informaticos]

You don't need o-scope.
I recommend to manually select DC volt scale, instead of auto range.