820-00165 no PM_SLP_S5_L pulls 0.06A

it-solve

Member
This board is a return case with liquid damage from 2 years ago. Not sure if related.
Stoped turning on, Seems like a screw got loose and got stuck between the GND of C7323 and the fan connector, Probably not related as well. Cant measure any direct shorts anywhere.

All voltages until PM_SLP_S5/4/3_L seem to be present.
PM_SLP_S5_L - 0V
PM_SLP_S4_L - 0.2V
PM_SLP_S3_L - 0V

Tried SMC_ONOFF_L and looked for pulses, I can't measure any pulses on ALL_SYS_PWRGD or any of the PM_SLPs.

I get a drop pulse on PM_PWRBTN_L with triggered - SMC_ONOFF_L

PP3V3_SUS - 0V
PM_SLP_SUS_L - 0V
PCH_INTRUDER_L - 0.02V
PM_DSW_PWRGD - 0.03V

Suggestions?
 
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it-solve

Member
PPVRTC_G3H - 0.11V at the output pin1
PP3V42_g3H - 3.4V
PP3v3S5 - 3.3V
PP3v3_TBTLC - 0.1V
PP3V3_S5RS3RS0_SYSCLKGEN - 3.3V
 
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it-solve

Member
Short on PPVRTC_G3H, removed caps in the line including U1900, still short. Seems to be coming from the CPU.

Dead CPU? Can I inject 2.5V to confirm?
 

2informaticos

Administrator
Staff member
Not the core; RTC is embedded into PCH.
However, PCH/CPU built on same package.

Just in case, add quality flux and heat that area.
There is a low chance of short caused by underneath corrosion.
 

it-solve

Member
Preheated it with a hot air gun, no luck - same heat spot.
I can try to reflow like a GPU but seems internal short.
2022-04-12 06-08-06.JPG
 
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