820-00840 Stuck on 5V

[2informaticos]

Any pulse at PM_SLP_S4_L, or drop pulse at PM_PWRBTN_L at least?
PM_RSMRST_L is high?

 

[brunomotter]

PM_SLP_S4_L no pulse
PM_RSMRST_L 0V
PM_PWRBTN_L Stays steady 3.3V when charger negotiates 20V with the board

 

[2informaticos]

If U7800 keeps PMIC_RSMRST_L down, PCH cannot react.
PM_PGOOD_P3V3S5 is present?

 

[brunomotter]

PM_PGOOD_P3V3S5 not present on Pin1 of R7903, if I measure on Pin 20 of U7650 it's pulsing.

 

[brunomotter]

Now PP3V3_S5 started pulsing also! WTF

 

[2informaticos]

Re-check solders and traces near U7650.
Test the board alone on the desk.
PPBUS_G3H is steady now?

 

[brunomotter]

Solder/traces are all ok. PPBUS_G3H steady 13V

 

[2informaticos]

Try now to start in SMC bypass mode.

 

[brunomotter]

No luck. PPBUS_G3H is stable, but PP3V3_S5 is pulsing like hell, in and out the case.

 

[2informaticos]

Do again the previous mode.
SMC_PM_G2_EN is stable?

 

[brunomotter]

SMC_PM_G2_EN pulsing like roller coaster

 

[2informaticos]

Looks like SMC detects some problem and cycles power sequence.

BTW, did you check it with that mode applied?

 

[brunomotter]

You mean in SMC bypass?

 

[2informaticos]

NO; as you've said already tried.
I mean to check if SMC_PM_G2_EN still fluctuates with the enable mod applied on U7650.
Try another 87W original charger also.

 

[brunomotter]

Gave up on this one. Costumer picked the machine up today as no repair. Thanks for all the help anyway.