820-00239-a 20v 0Amps

[NorwegianDude]

Got this board from another repair shop. While performing an battery change they bridged a component an saw a spark.
They think the bridge happened around C6950.

They had done some work with U7000 so i replaced this chip and missing caps.

PPBUS_G3H is 0.7V and no short.

Any assistance to where to go from here would be appreciated

 

[2informaticos]

Remove F7000 and check C7050 voltage.
3V3_G3H is present?

 

[NorwegianDude]

3v3_G3H is present 3.4 V

Checked C7050 after removing F7000 and it was 5v and then it went gradually down to 0.6 V. Very unstable as it sometimes stayed at 5v for 60 sec and then went down to 0.6 v

It also takes about 15 - 20 sec to negotiate 20V with charger. This also was the case before removing F7000

 

[2informaticos]

Post U7000 basic voltages: P_IN, AUX_DET, SMC_RST_IN, VDDA/P, SMC_RST*, AUX_OK, A/BMON.

 

[NorwegianDude]

P_IN : 20.41V
AUX_DET: 5.08V
SMC_RST_IN: 0V Not shorted
VDD A/P: 5.08V / 5.08V
SMC_RST* = 3.14
AUX_O = 3.41 V
A/BMON = 0V / 0V NO short

 

[2informaticos]

Look good.
Check R/C/Q7030/40 and their traces.

You may also have bad U7000, or solders.

 

[NorwegianDude]

Measured every trace and replaced U7000 with a new one.

Now PP3v3_G3H is missing and 5V on charger.
This is a fun one

 

[NorwegianDude]

Replaced U7000 with known good from donor and checked every trace around R/C/Q7030/40

Still have 0.7v on

PP3v3_G3H is now precent and 20V on charger.

Measured U7000 Basic voltages again, and they are the same as last time

 

[2informaticos]

F7000 is still removed?
Did you really check if Q7030/40 are good?

 

[NorwegianDude]

Hi had to put this one on hold, but yes checked both Q7030/40 and they are good.