820-4924 - No current draw - Missing PP3V3_S5 and PP5V_S5 after corrosion around SMBUS clock lines

[it-solve]

Corrosion on R530/31 Replaced both and repaired the PP3V3_S0_EDP_SW trace.
Reflowed the SMC to ensure gunk removed underneath.

Still no current draw at all. No shorts. Tried to bypass SMC.

from aliases table voltage stops here
PPVRTC_G3H = 3.4V
PP3V3_S5 = 0v
PP5V_S5 = 0v

No pulse on PM_SLP_S4_L on SMC_RESET_L repetitive trigger on my fluke.


Any advice? Would SMC control S5 power lines? Reball SMC?

 

[2informaticos]

You can't expect any pulse from PCH, since 3V3_S5 isn't present.

What exact voltage fro PPBUS_G3H and 3V42_G3H?

 

[it-solve]

PPBUS_G3H - 12.28V
3V42_G3H - 3.42V

 

[2informaticos]

Post U5110 voltages.

 

[it-solve]

PP3V42_g3h - 3.42V
PP3V42_G3H_SMC_SPSR - 3.42v
SMC_MANUAL_RST_L - 2.76V
SMC_RESET_L - 0.11V
SMC_TPAD_RESET_L - 3.40V
SMC_ONOFF_L - 3.41V
PP3V3_S5_AVREF_SMC - 3.29V

 

[2informaticos]

Fix SMC_RESET_L issue.
Check diode mode first.
Inspect J6100 for corrosion.

 

[it-solve]

U5110 seem to get the voltages it needs. Replaced it but still SMC_RESET_L stays at 0.12V
Also replaced U7100 thinking that it might have internal failure and might be pulling SMC_RESET_L down, but no difference still SMC_RESET_L stays at 0.12V

Diode mode of U5110 aligns with a spare board i have.

No corrosion anywhere apart than the SMC spot here



Only other place I see SMC_RESET_L is heading to SMC. Shall I replace SMC? I have a spare same board

 

[2informaticos]

Did you inspect J6100?
Just in case, force R5100 with 10K, instead of 100K.

You can reball SMC first; if still same, replace it.

 

[it-solve]

Replaced R5100 with 10K, SMC_RESET_L went up to 0.15V but that's it.
Diode mode on SMC_RESET_L is 0.505Vdc

No corrosion on J6100, there was only around the SMC