820-3437 - short SMC

[Palhano]

I found it short on line 3.42, caused by the SMC. Replaces and the short ended, but the board doesn't turn on, I tried with another SMC, same thing.

RTC_RESET_L - 3.26V
SHP_INTRUDER_L - 1.65v
PCH_INTVRMEN - 2.5v
SHP_SRTCRST_L - 3.26V

PPBUS_G3H - 8.6
PP3V42_G3H - 3.4v
PPVRTC_G3H - 3.3V
PP5V_S5 - 5v
PP3V3_S5 - 3.3V
*PP3V3_SUS - 0
SMC_ONOFF_L - 3.37v


*SMC_ADAPTER_EN - 0
SMC_PM_G2_EN - 3.4V
PM_BATLOW_L - 3.3V
*PM_PWRBTN_L - 0.34
*PM_RSMRST_L - 0
*PLT_RESET_L - 0
*ALL_SYS_PWRGD - 0

 

[2informaticos]

"SHP_INTRUDER_L - 1.65v"
Do you mean PCH_INTRUDER_L?
If yes, then is low enough to block PCH starting power on sequence.

Possibly accumulated crap under PCH area.
Heat it with quality flux; no more than 180-200 degrees, for 15-20s.

 

[Palhano]

Yes, PCH_INTRUDER_L! I don't know why, but the cell phone always changes that! haha

I've already tried to heat it up, it didn't work!

 

[2informaticos]

Force the signal, using 100K resistor, instead of 1M.

 

[Palhano]

with 100k, I have 3v in PCH_INTRUDER_L. But only this.

 

[2informaticos]

Check PM_DSW_PWRGD.

 

[Palhano]

PM_DSW_PWRGD - 0v

 

[2informaticos]

It should be high, if you have stable 3V3_S5.
Check R8141.

 

[Palhano]

3V3_S5 is stable.

R8141 is perfect!

 

[2informaticos]

S5_PWRGD voltage?

 

[Palhano]

Sorry, forgot voltages on R8141.

S5_PWRGD - 3v
PP3V42 - 3.35v

 

[2informaticos]

Check R5192 and SMC_S5_PWRGD_VIN voltage.

 

[Palhano]

R8141 is perfect - 100k - Traces, okay.

SMC_S5_PWRGD_VIN - 3v
PP3V42 - 3.35v

 

[2informaticos]

Then SMC is suspect.
Did you use correct SMC, from donor board?

 

[Palhano]

yes, i took it from an 820-3437 board! I'll try to get another SMC!