820-01041-A no power.

[Sr. Robot]

Got a 820-01041-A that does not show signs of life. No visible damage.

The T2 chip is heating a bit.

PPBUS_G3H = 12.57v
PP3V3_G3H_SOCPMU = 3.3v
PPVCC_S0_CPU = 0v
PP5V_G3S = 5,13 then drops to 0v and again.

 

[2informaticos]

Did you try to put in DFU?

 

[Sr. Robot]

it connects but gives error when restoring

 

[2informaticos]

Board switches from 5V to 20V?
Check w/ and w/o battery.

Be sure to use 87/96W charger.
Try DFU with both charger and battery connected.
Connect charger before DFU cable.

 

[Sr. Robot]

I get steady 20v on PP20V_USBC_XB_VBUS with the battery disconnected.

If the battery is connected then PP20V_USBC_XB_VBUS is 5v.

Charger is 96W.

Tried DFU with and without battery. Same thing.
Also charger connected first.

 

[2informaticos]

All USB-C ports have the same behavior?
Test them in both ways connection.

Is the battery charging?

 

[Sr. Robot]

Yes, all 4 ports go from 5v to 20v w/o battery

All 4 ports stuck on 5v with battery.

Ports doesnt work the other way around.

SCL/SDA = 3.3v

PPVBAT_G3H_CONN

I dont have usb amp meter. How can i check if battery is charging?

 

[2informaticos]

If the battery really charges, PPBUS_G3H increases slowly; unless battery is full 100%.

 

[Sr. Robot]

PPBUS_G3H went from 12.62v to 13.02 in about 20 secs

 

[2informaticos]

What kind of error do you get in DFU?

Just in case, try with empty SoC ROM.
Don't forget to make backup first.

 

[Sr. Robot]

It gives me the same error: "Unexpected device state ´DFU´ expected ´Recovery´ (Probable forced into DFU mode externally)
[.com.apple.MobileDevice.MobileRestore - 0xFAE (4014)]

 

[2informaticos]

Check diode mode to ground on all secondary power rails.
Don't forget SSD rails...

 

[Sr. Robot]

PPVCCPRIMCORE_PRIM_REG is 45 ohms to ground.

Diode mode:

PPVCC_S0_CPU .0000
PPVCCSA_S0_CPU 0.0004
PPVCCGT_S0_CPU 0.0001
PPVCCIO_S0_CPU 0.012
PP1V2_S3 0.05
PP1V2_S3_CPUDDR 0.05
PP1V05_PRIM 0.024
PPVCORE_S0_GPU 0.0000
PPVDDCI_S0_GPU 0.013
PP1V5R1V35_S0_GPU_MEM 0.021
PP1V5R1V35_S0_GPU_IC 0.021

Those are the rails where i got low resistances.

 

[2informaticos]

CPU/GPU core coils have very low calues as normal.
However, VCCSA is possibly too low.
You should compare these values with good board.

BTW, use ohm scale for low readings in diode mode.