820-00840 - PP3V3_G3H at 2.26V

[Pavel]

Hello everybody !

The charger is stuck at 5V - 0amps.

PP3V3_G3H gets dragged down to 2.26v for an unknow reason. If I remove the resistor R6999, pin 1 gives me 3.4v. Resistance in diode mode (red probe on ground) on pin 2 is 0.395 and another way (black probe on ground) is 0.822

I've tried voltage injection, but it's not drawing any current.

Any idea ,what's going on?

 

[2informaticos]

Check diode mode to ground around CD3215 chips.
Start with their LDOs.

 

[Pavel]

Thank you for your answer!
Which LDOs do you mean ?

 

[2informaticos]

Look at pages 29/30 in schematic.
I'm pretty sure you will find some lines with "LDO" in their names...

 

[Pavel]

Thank you! I was. So
I don't have PP1V1_UPC_XB_LDO_BMC for both ports and strange with PP3V3_UPC_XA_LDO and PP3V3_UPC_XB_LDO
I have got PP3V3_UPC_XB_LDO is 2.2v and PP3V3_UPC_XA_LDO is 3.3v for one port
And PP3V3_UPC_XB_LDO is 3.3v and PP3V3_UPC_XA_LDO is 2.2v for another

 

[2informaticos]

"Check diode mode to ground..."
Pay atention when read the posts.

BTW, 1V1 LDO voltage should appear only on the powered port.

 

[Pavel]

sorry for my stooped question I have compered main lines with another board and nothing difference ....
any idea?

 

[2informaticos]

Then the low reading on 3V3_G3H should be caused by other chip, not CD3215.
That will be more dificult to locate...

 

[Pavel]

no idea ?

 

[2informaticos]

Inject 3.5V and use thermal camera.
May need to wait several minutes.

 

[Pavel]

Just 11 mA if I inject 3.4v on L6995 and nothing ....
Cant see any hot in thermal camera of cause

 

[2informaticos]

Did you resolder R6999???

 

[Pavel]

I did it before, it was the same.
Now i inject with R6999