820-00928 No Power

iClub

Member
Good afternoon this mac has suffered oxidation in the U4200, U3500, and U3100 regions. I replaced the oxidized components, it worked for a while. The customer returned with the defect of an unexpected shutdown. Now no PPBUS.

I had made a post earlier.


U3200 mode diode/ Voltage
PP1V8_UPC_XB_LDOD 0.487V 1.80v
PP3V3_UPC_XB_LDO 0,507 3,33v
PP1V1_UPC_XB_LDO_BMC 0,520V 0v
PP1V8_UPC_XB_LDOA 0,527V 1,82v


U3100

PP1V8_UPC_XB_LDOD 0,491V 1,82V
PP3V3_UPC_XB_LDO 0,511V 3,33V
PP1V1_UPC_XB_LDO_BMC 0,522V 0V
PP1V8_UPC_XB_LDOA 0,530V 1,79V
UB400

PP1V8_UPC_TB_LDOD 0,487V 1,8V
PP3V3_UPC_TB_LDO 0,512V 3,2V
PP1V1_UPC_TB_LDO_BMC 0,510V 0V
PP1V8_UPC_TB_LDOA 0,527V 1,8v

UB300

PP1V8_UPC_TB_LDOD 0,489V 1,8v
PP3V3_UPC_TB_LDO 0,513V 3,31V
PP1V1_UPC_TB_LDO_BMC 0,522V 0V
PP1V8_UPC_TB_LDOA 0,528V 1,8v

PPBUS 0,123V
PP3V3_G3H 0V
PPVIN_G3H_P3V3G3H 0v
PP20V_USBC 20V only where the charger is connected
 

2informaticos

Administrator
Staff member
How do you get 20V without 3V3_G3H?
This is really strange.

"PP3V3_G3H 0V
PPVIN_G3H_P3V3G3H 0v"
Check again these voltages; especially when you get 20V at USB-C meter.
If not present, check diode mode to ground on both.
 

iClub

Member
mode diode
PPVIN_G3H_P3V3G3H 0V,no pulse. 0,557V
PP3V3_G3H 0V, no pulse 0,370V
FB200 20,11V

I had changed u3100 earlier, I forgot to comment.
 

iClub

Member
R5210, R3035, and R3035 are not on the board. Does it come on the board or is it missing?
 

2informaticos

Administrator
Staff member
So you have problem located in USB-C areas.
More components affected by corrosion.

Post C3101 voltage.
Connect charger to its corresponding port.
 

iClub

Member
Suddenly the mac turned on using another charger.
I left it in tests and out of nowhere it turned off and won't turn on anymore. It is intermittent, out of nowhere it turns on.
I would like to know if the components I already replaced are U4200, U3906, U4401, U5850 and U3100 ?


PPBUS 12,6V
 
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