820-00840 No PP3V3_G3H

cwalex

New member
Hi,

I have dead 820-00840. It had liquid damage around U2890 which I cleaned up and ran jumper wires etc. 5V on the USB C power meter.

I have:
PP3V3_G3H = 0.17V
PM_EN_P3V3_G3H_R = 0V

Neither are short to gnd. Any help from here would be appreciated.
 

2informaticos

Administrator
Staff member
Be sure all resistors around U2890 are OK and check continuity to its pins.
Possibly broken trace between U2800/90.
In such case, USB-C controllers never work.

Voltage to R7020?
 

cwalex

New member
PP20V_USBC_XA_VBUS=5V but PPDCIN_G3H=0V. Don't I need this rail before U7000 is suspect? The power system on these boards makes my brain hurt.
 

JohnB8812

New member
If you don?t even have PPDCIN check for a short on that line. Also for sure known good 87 watt USBC brick and cable? Also ports aren?t badly corroded?
 

2informaticos

Administrator
Staff member
Compare voltage and resistance to ground (diode mode) at LDO outputs for both CD3215 chips.
Don't forget to check for short, or low value at PPDCIN_G3H.
Will be better if you have known good board, to compare all values.
 

cwalex

New member
Compare voltage and resistance to ground (diode mode) at LDO outputs for both CD3215 chips.
Don't forget to check for short, or low value at PPDCIN_G3H.
Will be better if you have known good board, to compare all values.
No short on PPDCIN_G3H

Faulty board
PP3V3_UPC_XA_LDO=0.486V
PP3V3_UPC_XB_LDO=0.498V

Good board
PP3V3_UPC_XA_LDO=0.515V
PP3V3_UPC_XB_LDO=0.515V


If you don?t even have PPDCIN check for a short on that line. Also for sure known good 87 watt USBC brick and cable? Also ports aren?t badly corroded?
No short to gnd on that line. Using a good 87W charger and cable.
 
Last edited:

cwalex

New member
Good board (diode mode):
PP1V8_UPC_XA_LDOD=0.483V
PP3V3_UPC_XA_LDO=0.515V
PP1V8_UPC_XA_LDOA=0.525V
PP1V1_UPC_XA_LDO_BMC=0.520V
PP1V8_UPC_XB_LDOD=0.484V
PP3V3_UPC_XB_LDO=0.515V
PP1V8_UPC_XB_LDOA=0.525V
PP1V1_UPC_XB_LDO_BMC=0.520V

Faulty board (diode mode):
PP1V8_UPC_XA_LDOD=0V!
PP3V3_UPC_XA_LDO=0.483V
PP1V8_UPC_XA_LDOA=0.526V
PP1V1_UPC_XA_LDO_BMC=0V!
PP1V8_UPC_XB_LDOD=0.494V
PP3V3_UPC_XB_LDO=0.495V
PP1V8_UPC_XB_LDOA=0.535V
PP1V1_UPC_XB_LDO_BMC=0V!

Faulty board (Voltages):
PP1V8_UPC_XA_LDOD=0V
PP3V3_UPC_XA_LDO=0.094V
PP1V8_UPC_XA_LDOA=0V
PP1V1_UPC_XA_LDO_BMC=0V
PP1V8_UPC_XB_LDOD=0V
PP3V3_UPC_XB_LDO=1.547V
PP1V8_UPC_XB_LDOA=0V
PP1V1_UPC_XB_LDO_BMC=0V

I guess that's why I don't have PPDCIN_G3H.
 

2informaticos

Administrator
Staff member
"PP1V8_UPC_XA_LDOD=0V!" (diode mode)
So you have a short there.
Check C3105, but I bet U3100 is the culprit...
 

cwalex

New member
Replaced U3100, I now have PPDCIN_G3H=5V. PP3V3_G3H is ~2.9V. When I plug the USB C power meter in to the port connected to U3100 I get 5V and ~400mA but on the port connected to U3200 I get 5V ~170mA. Does that sound like U3200 is bad as well or that I goofed soldering U3100?
 

cwalex

New member
Readings after replacing U3100

Faulty board (diode mode):
PP1V8_UPC_XA_LDOD=0.492V
PP3V3_UPC_XA_LDO=0.506V
PP1V8_UPC_XA_LDOA=0.534V
PP1V1_UPC_XA_LDO_BMC=0.530V
PP1V8_UPC_XB_LDOD=0.494V
PP3V3_UPC_XB_LDO=0.495V
PP1V8_UPC_XB_LDOA=0.535V
PP1V1_UPC_XB_LDO_BMC=0.529V

Faulty board (Voltages):
PP1V8_UPC_XA_LDOD=1.817V
PP3V3_UPC_XA_LDO=3.325V
PP1V8_UPC_XA_LDOA=1.793V
PP1V1_UPC_XA_LDO_BMC=0V
PP1V8_UPC_XB_LDOD=1.375V
PP3V3_UPC_XB_LDO=2.32V
PP1V8_UPC_XB_LDOA=0V
PP1V1_UPC_XB_LDO_BMC=0V
 

2informaticos

Administrator
Staff member
When you check B port voltages, plug the charger on the corresponding USB-C port.
And compare again with good board.

PP3V3_G3H is low on both cases?
Check it on R6999.
 

cwalex

New member
Plugged into corresponding ports.
PP1V8_UPC_XA_LDOD=1.8V
PP3V3_UPC_XA_LDO=3.3V
PP1V8_UPC_XA_LDOA=1.8V
PP1V1_UPC_XA_LDO_BMC=0V
PP1V8_UPC_XB_LDOD=0.5V
PP3V3_UPC_XB_LDO=1.5V
PP1V8_UPC_XB_LDOA=0V
PP1V1_UPC_XB_LDO_BMC=0V

PP3V3_G3H=0.1V when plugged into port corresponding to B and 2.9V when plugged into A.

Comparing the diode mode readings to the good board they are all very close.
 

cwalex

New member
Here are the readings anyway.

Good board (diode mode):
PP1V8_UPC_XA_LDOD=0.483V
PP3V3_UPC_XA_LDO=0.515V
PP1V8_UPC_XA_LDOA=0.525V
PP1V1_UPC_XA_LDO_BMC=0.520V
PP1V8_UPC_XB_LDOD=0.484V
PP3V3_UPC_XB_LDO=0.515V
PP1V8_UPC_XB_LDOA=0.525V
PP1V1_UPC_XB_LDO_BMC=0.520V


Faulty board (diode mode):
PP1V8_UPC_XA_LDOD=0.492V
PP3V3_UPC_XA_LDO=0.506V
PP1V8_UPC_XA_LDOA=0.534V
PP1V1_UPC_XA_LDO_BMC=0.530V
PP1V8_UPC_XB_LDOD=0.494V
PP3V3_UPC_XB_LDO=0.495V
PP1V8_UPC_XB_LDOA=0.535V
PP1V1_UPC_XB_LDO_BMC=0.529V
 
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