[SOLVED]820-01987 Minor Liquid Damage 5V on charger

brunomotter

Member
Hello. Got an 820-01987 board here with liquid spill. Originally liquid was near U6903 and C10G1. I cleaned everything, gave a nice reflow with lots of Amtech flux on U6903 and still cannot get charger to negotiate 20V. Both ports give 5V stuck. U6903 is responsible for RTC, but there are no shorts near it nor anywhere on the board. Where to start? I have very little experience with these new boards with USB-C charging, trying to understand it's architecture, but I'm not very smart LOL.
 

2informaticos

Administrator
Staff member
Do you get now 3V3_G3H_RTC?
Also check all SLPS2R and AWAKE voltages.
If present, then see if machine is detected in DFU mode.
 

brunomotter

Member
PP3V3_G3H_RTC - 0V
PP1V8_SLPS2R - 0V
PP1V25_SLPS2R_SMC_AVREF - 0.2V oscillating
PP0V8_SLPS2R - 0V
PP1V1_SLPS2R - 0V
 

brunomotter

Member
PPVIN_G3H_P3V3G3HRTC - 12.24V
CHGR_EN_MVR_R - 5.14V
P3V3G3HRTC_PGOOD - 0V
PP3V3_G3H_RTC_REG_R - 0V
P3V3G3HRTC_PHASE1 - 0V
P3V3G3HRTC_PHASE2 - 0V
P3V3G3HRTC_FB - 0V


C6907 - 0.4214
 

2informaticos

Administrator
Staff member
Check R6910-13 and their traces.
Be sure to have good solders/traces for U6903; you may need to replace it.
 

brunomotter

Member
Verified resistors and traces and all seems normal... Probably chip gone bad because of corrosion. Will need to order from China as I don't have any donor boards here.
 

brunomotter

Member
Hello! Just posting feedback here. I ordered the chip from AliExpress. Replaced it and now the board works again! Thanks AGAIN for all the help. You are the man! Whenever I go to Madrid I'm gonna pay you a couple of beers. Thanks one more time.
 
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