820-00840: PP20V_USBC: 5v and not powering up

Hello
Have this board that had corrosion damage. Repaired all the miss obvious missing traces. Replaced both CD3215 chips, along with blown resistors. Also replace U7000. I've reflashed a clean ME and also a complete BIOS. Still not powering up.

Here are the readings i have so far:

PP3V3_G3H: 3.4
SMC_RESET_L: 3.4
BUF_SMC_RESET_L.: 3.4
PPBUS_G3H: -0.13 (yeah these readings were erratic. I confirmed on oscope, it is generating negative voltage). On one instance, i had 0.3V reading.
PPBUS_G3H Diode mode: 0.43
TBA_VDDA: 5.2
TBA_VDDP: 5.2
PP1V1_UPC_XA_LDO_BMC: 0
PP1V1_UPC_XB_LDO_BMC: 0

Any suggestions.
 

2informaticos

Administrator
Staff member
You still have problems on USB-C areas; why did you touch the BIOS???
Check all LDO for CD3215 chips.
Compare diode mode readings with known good board.
 

2informaticos

Administrator
Staff member
Any board with CD3215 can serve for comparison.

Main BIOS is not involved in charger detection and power delivery protocol.
 

2informaticos

Administrator
Staff member
If you do npt get 1V1 LDO on the activated port, should be a problem with CD3215 chip.
You can try the trick to bypass IN-OUT the correspondintg MOSFET nand see if get 20V on USB-C port.
It probably doesn't work with problems on both ports, but worth to try...
 
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