820-00281 does not charge. PPBUS_G3H low on battery

[arash]

This device had liquid damage. It did not turn on.
I have changed U7000. One pin of the chip was "burned". After that the device did turn on. but only in smc bypass mode.
if i try it to boot normally it show me battery low symbol. I have already tried a new battery.
PPBUS_G3H with battery only connected is only 3V.
Both I2C lines (SDA/SDC) from battery connector show almost same dioode mode reaeding (approx 0.3V)
what could be the issue here? the cd3215 chips ??

 

[2informaticos]

Cannot be USB-C issue, if machine starts in SMC bypass.
Post exact resistance over C7020/23; between their pins I mean.

 

[arash]

C7020 Resistance: 2.7 ohm. C7023: 2.8 ohm

 

[2informaticos]

Which pin of U7000 was burnt?
Post exact voltage for PPBUS_G3H (without battery).

 

[arash]

i dont know anymore :/ i belive pin 3. PPBUS_G3H without battery is 12.61V

 

[2informaticos]

PPBUS_G3H is correct then.
If you connect battery, it will drop, according with battery level.
The voltage will increase and go back to 12.6V, once battery is fully charged.

 

[arash]

But it does not charge it. nor will it run on an already charged battery

 

[2informaticos]

PPBUS_G3H stays at 12.6V even with battery connected?

Do you have now good contact for all U7000 balls?
Check SMC_BC_ACOK and CHGR_A/BMON.

 

[SMMRepair]

Inspect areas immediately near USB-C connectors on board. VERY common for people to knock off the diodes/caps when disconnecting the USB-C assembly.

 

[arash]

@2informaticos Should i measure ACOK and A/BMON with battery connected ?

 

[arash]

PPBUS_G3H 12,58 with battery connected.

 

[2informaticos]

A/BMON better to measure with battery connected.
Then will reflect battery charging current, if charges...

 

[arash]

@2informaticos CHGR_AMON 300mV when it turns on (fan spins) and 0mV when its off. CHRG_BMON is always 0mV.
Wich voltage should i expect on PPVBAT_G3H_CONN???. i do have I2C communiaction on SDA and SCL lines

 

[2informaticos]

Try another battery.
Better old one, known good working, just for test.

 

[arash]

i did. still same behavior

 

[2informaticos]

macOS recognizes battery?
Look in System Report too.

 

[arash]

now it crashes if itry to boot in smc-bypass mode

 

[2informaticos]

All USB-C ports switch to 20V?
PPBUS_G3H correct and stable?
Did you try SMC bypass without battery connected?

 

[SMMRepair]

I just remembered something I saw recently, and just to be safe: Make sure you have the battery communication cable right-side-up. Had a customer with similar issues and it turned out he had his battery cable installed upside down...