820-00840 water damage dead.

[yair37]

get it from other lab they try to fix and clean, the water damage was at the backlight erea.
i get 20v at charger.
ppbus-13v
pp3v3 is 3.3v
pp5v_s0 0v

U7650 voltage:
Pin 12 is 0
pin 21 is 0
pin 23 is 13.10 volts

SMC_PM_G2_EN 3.3v

 

[2informaticos]

Check PM_EN_P3V3S5.
If low, check U7800 LDO voltages.

 

[yair37]

Check PM_EN_P3V3S5.

0v

If low, check U7800 LDO voltages.

pp3v3_LDO3V 3.3V
PP5V5_LDO5V 5V

 

[2informaticos]

PMIC_SHUTDOWN_L stays high?
No pulse detected at PM_EN_P3V3S5 when connect the charger?
PP1V25_VREF and PP3V1_RTC both good?

 

[yair37]

PMIC_SHUTDOWN_L stays high?

3.3V stable.

No pulse detected at PM_EN_P3V3S5 when connect the charger?

no, stable 0v

PP1V25_VREF and PP3V1_RTC both good?

yes both good. 1.2v and 3.1v stable

 

[2informaticos]

Looks like bad U7800.

 

[yair37]

replaced... the same

 

[2informaticos]

Maybe some broken trace, or damaged resistor.

 

[yair37]

where? near U7800?

 

[2informaticos]

Yes, as U7800 seems to get required voltages and signals.

 

[yair37]

PM_EN_P3V3S5 this is the important rail to get voltage?
when i have this it mean that U7800 is o.k?

 

[yair37]

and can u7650 can be the problem?

 

[yair37]

o.k i was replaced U7650 now i have pin 12 (P5VVX_EN) 3.4V and pin 21 (P3V3S5_EN) 3.4V but still PM_EN_P3V3S5 0.03 when plug charger.

 

[2informaticos]

How is that possible???
P3V3S5_EN comes from PM_EN_P3V3S5; check schematic...

 

[yair37]

I sew that but i was checking 10 times
Pin 21 get 3.4v R7784 get 0.01

 

[yair37]

sorry R7884 and yes is PM_EN_P3V3S5G and there is no PM_EN_P3V3S5 on board
And R7662 is…https://ibb.co/G2gZzZx

 

[yair37]

R7662 IS 3.4V both side of course.
U7890 pin 5 is unconnected do you mean pin 2? pin 2 3.4v pin 4 3.3v

 

[2informaticos]

Then you must have 3V3_S5 at L7690.