820-00239 no power, missing PPbus_g3h.

iClub

Member
hello friend all good ?
I'm with this mac that suffered contact with liquid in the UB400,UB300 components and the PPVIN_2V7NAND_LB mesh, where R9350 was corroded, I remade the broken track and replace the r9350.
The voltages of the board are:
PPBUS_G3H 0v
PP20V_USBC_XB_VBUS 0V ~ 5.08V
PP3V3_G3H 3.49V ~ 0V
PP3V3_UPC_XB_LDO 1.50V ~ 3.3V
PP5V_S4_X_USBC 0v
I hope that these measures will help to understand the problem! :)
 

2informaticos

Administrator
Staff member
"PP20V_USBC_XB_VBUS 0V ~ 5.08V "
Does this mean you have 20V at the other 3 USB-C ports?
If not, I don't understand why do you post the voltage for one port only...

"PP3V3_G3H 3.49V ~ 0V "
The board cannot start, if 3v3_G3H is not steady; SMC will not work and obviously impossible to get 20V at any USB-C port.

Compare diode mode readings at LDO outputs between all CD3215 chips; each one has 4 LDO outputs!
Do you get steady 5V at R7020?
 

iClub

Member
Faixa de diodo nas saídas LDO nos chips U3200, UB400, UB300, U3100:
----> U3200
-PP1V8_UPC_XB_LDOD 0.506V
-PP3V3_UPC_XB_LDO 0.535V
-PP1V1_UPC_XB_LDO_BMC 0.540V
-PP1V8_UPC_XB_LDOA 0.544V
----> UB400
-PP1V8_UPC_XB_LDOD 0.506V
-PP3V3_UPC_XB_LDO 0.530V
-PP1V1_UPC_XB_LDO_BMC 0.519V
-PP1V8_UPC_XB_LDOA 0.544V

----> UB300
-PP1V8_UPC_XB_LDOD 0.508V
-PP3V3_UPC_XB_LDO 0.542V
-PP1V1_UPC_XB_LDO_BMC 0.545V
-PP1V8_UPC_XB_LDOA 0.549V

---> U3100
-PP1V8_UPC_XB_LDOD 0.509V
-PP3V3_UPC_XB_LDO 0.530V
-PP1V1_UPC_XB_LDO_BMC 0.544V
-PP1V8_UPC_XB_LDOA 0.548V
 

iClub

Member
It replaces the UB400, but it didn't solve.

PP20V_USBC_TB_VBUS 0V
PP1V8_UPC_TB_LDOD 1.7V
PP3V3_UPC_TB_LDO 3.3V
PP5V_S4_T_USBC 0V
PP3V3_G3H 3.3V
PPBUS_G3H 54mV:
 

iClub

Member
ub3200
PP1V1_UPC_TA_LDO_BMC 1.118V is oscillating.

U3100
PP1V1_UPC_TA_LDO_BMC 1.118V, oscillating

UB400
PP1V1_UPC_TA_LDO_BMC 0V

UB300
PP1V1_UPC_TA_LDO_BMC 0V
 

2informaticos

Administrator
Staff member
Something else affected by liquid on UB300/400 area.
Can be UB000/90, or a simple cap, or resistor.
These chips are also connected to CPU, so damage can be worst.
 

iClub

Member
I have replaced UB400 and nearby oxidized components, but the PPBUS is still at 100mV. could it be the U5000? How can I identify my measurements?
I would really like to solve this mac, I am trying for almost a year.
 
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