820-00850: Not powering up. PP20V_USBC 5v

Hello

Got this board liquid damage. Customer had already cleaned the board. Corroded RB631. Replaced resistor and also retraced a new line from RB631 pin2 to RB651pin2 as it's pad was missing. Also replaced QB631 due to signs of corrosion. Still won't power up.
Found L6900/01 missing. Replaced. Still won't power up.
Took below measurements

PPBUS_G3H - 12.2
PPDCIN_G3H - 5.17
PP3V3_G3H - 3.4
PP20V_USBC - 5.17

So replaced all the CD3215C chips with exact chips numbers. Still have the same result. Any other suggestions or is this dead board?
 

2informaticos

Administrator
Staff member
Yes U6940, sorry for mystyping.
No datasheet needed it here.
Post EXACT voltage for its pin10 and previous signals mentioned.
 

2informaticos

Administrator
Staff member
Let me be more specific; looks like you didn't understand me.
Poste exact (two decimals) voltage for CHGR_RST_IN_R, CHGR_RST_IN and UPC_PMU_RESET.
We need to see which side of output resistors is pulled down.
If all are 0.0V, or CHGR_RST_IN_R is the lowest, then change U6940.
 

2informaticos

Administrator
Staff member
Isn't U6940???
If has 3V at pins 1, 3, 4, then must have 3V at output pin 10.
Remove R6940/41 and check that; supposing a pull-up resistor is inside U6940.
 
Yeah, I meant U6940. I pulled U6940 with the same readings on 1, 3, 4 and 10. Also, there is no U6941 on this board.
I agree with you that pin 10 should have 3v. It's possible the replacement chip I pulled from a donor board is also bad. Unfortunately I can't find a replacement online anywhere. Going to have to see if I can find another donor board or a board that has this chip on.
 
Yeah I kinda figured it was. Currently searching for possible substitute. Can?t find the chip anywhere without pulling from a donor board.
 
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