820-01041 stucks at 5v

dudipupan

Member
Hi there,

i'm very new with the newer USB-C MLBs and got a water damaged 820-01041 here that stucks at 5V 0.4A. It had some corrosion around U3200.
I replaced some corroded components like Q3200, F3001, C3509, C3505, CC753 and CB212.
The board took 4.8V and 0.6 A on 3 of 4 USB-C ports and 5V 0.1A on the last one. On the 0.1A port PPBUS_G3H and PP3V3_G3H was missing - with the other 3 ports it was present. So i replaced U3200 (the associated CD3215A for the 0.1A port).
Not the board takes 5.02V and 0.41A on all four ports.
PPBUS_G3H is stable with 12.31V.
0.4A seems very high for 5V?
Any hints how to go on?
I will start to check all rails for short to ground now.

Thanks and best regards
Dudi
 

dudipupan

Member
I did some diode mode measurements of the LDO outputs of the CD3215 chips:

U3100​
PP3V3_UPC_XA_LDO​
0,485​
PP3V3_TBT_X_SX​
0,506​
PP1V8_UPC_XA_LDOA​
0,491​
PP1V8_UPC_XA_LDOD​
0,453​
PP1V1_UPC_XA_LDO_BMC​
0,476​
U3200​
PP3V3_UPC_XB_LDO​
0,481​
PP3V3_TBT_X_SX​
0,505​
PP1V8_UPC_XB_LDOA​
0,498​
PP1V8_UPC_XB_LDOD​
0,461​
PP1V1_UPC_XB_LDO_BMC​
0,492​
UB300​
PP3V3_UPC_TA_LDO​
0,485​
PP3V3_TBT_T_SX​
0,507​
PP1V8_UPC_TA_LDOA​
0,494​
PP1V8_UPC_TA_LDOD​
0,458​
PP1V1_UPC_TA_LDO_BMC​
0,488​
UB400​
PP3V3_UPC_TB_LDO​
0,485​
PP3V3_TBT_T_SX​
0,507​
PP1V8_UPC_TB_LDOA​
0,494​
PP1V8_UPC_TB_LDOD​
0,458​
PP1V1_UPC_TB_LDO_BMC​
0,484​
 

dudipupan

Member
And also the keyboard and trackpad connector has some corrosion on it, such as area around U5104 (checked this area already for shorts to ground)
 

2informaticos

Administrator
Staff member
Which other voltages do you get on the board?
Test if machine is recognized in DFU mode.

0.4A is too high for actual symptom.
A thermal cam can help you, to detect the culprit.
You can try to change U3100 too.

We've got diode mode readings, what about voltage of these rails?
 

dudipupan

Member
I replaced U3100 too what resulted in a small increase of voltage on all 4 ports (5.14V now).
DFU mode seems not to work. Du I have to set the macbook i want to restore actively in DFU mode (power btn + right shift + left option + left control) or will it atumatically activate DFU mode on plugin (thats what it looked like on a video from louis)?

Here some more measurements:


U3100​
Diode Mode​
Voltage (V)​
PP3V3_UPC_XA_LDO​
0,482​
3.39​
PP3V3_TBT_X_SX​
0,506​
0.0​
PP1V8_UPC_XA_LDOA​
0,493​
1.79​
PP1V8_UPC_XA_LDOD​
0,457​
1.78​
PP1V1_UPC_XA_LDO_BMC​
0,484​
0.0​
U3200​
PP3V3_UPC_XB_LDO​
0,481​
3.3​
PP3V3_TBT_X_SX​
0,505​
0.0​
PP1V8_UPC_XB_LDOA​
0,498​
1.82​
PP1V8_UPC_XB_LDOD​
0,461​
1.8​
PP1V1_UPC_XB_LDO_BMC​
0,492​
0.0​
UB300​
PP3V3_UPC_TA_LDO​
0,485​
3.34​
PP3V3_TBT_T_SX​
0,507​
0.0​
PP1V8_UPC_TA_LDOA​
0,494​
1.8​
PP1V8_UPC_TA_LDOD​
0,458​
1.79​
PP1V1_UPC_TA_LDO_BMC​
0,488​
1.11​
UB400​
PP3V3_UPC_TB_LDO​
0,485​
3.3​
PP3V3_TBT_T_SX​
0,507​
0.0​
PP1V8_UPC_TB_LDOA​
0,494​
1.8​
PP1V8_UPC_TB_LDOD​
0,458​
1.8​
PP1V1_UPC_TB_LDO_BMC​
0,484​
0.0​
Resistance (Ohm)​
Voltage (V)​
PPBUS_G3H​
3.5k​
12.31​
PP3V3_G3H_T​
3.32​
PP3V3_G3H_RTC_X​
3.39​
PP1V8_G3S​
3k​
0.0​
PP5V_G3S​
1.8k​
0.0​
PP3V3_G3S_T​
28k​
0.0​
PP3V3_G3S_X​
3.2k​
0.0​
PP3V3_S0SW_TBT_X​
8.5k​
0.0​
PP3V3_S0SW_TBT_T​
8.6k​
0.0​
PP1V05_PRIM​
68​
0.0​
PP1V8_SLPS2R​
1.8​
PP0V8_SLPS2R​
0.8​
PP1V1_SLPS2R​
1.1​
PMU_ONOFF_L​
3.38​
PMU_RSLOC_RST_L​
3.38​
CHRG_RST_OM_R​
470k​
0.0​
PP1V2_S3​
220​
0.0​
PP2V5_S3​
1.5k​
0.0​
 

2informaticos

Administrator
Staff member
1V1 LDO must appear only on the CD3215 corresponding to powered port.

If all SLPS2R and AWAKE voltages are present, machine should enter DFU.
Some information here.
 

dudipupan

Member
I was able to start it in DFU mode now. I started to restore. I still don't get any display or fan spin. How can I know when it is finished? Will leave it like this for a while now.
 

2informaticos

Administrator
Staff member
DFU is not completed.
There should be T2, SSD, or CPU issue.
Less probably to be CPU problem, as it doesn't even switch to 20V; more likely T2 issue.

Did you try Revive option too?
 
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