820-00875

[Mac Tech]

Hello, greetings to all.

This plate got liquid on it.

The problem is that it does not recognize the battery, it only turns on with the charger.

When connecting the battery the voltage on ppbus_g3h is 12.28V.

SDA line 0v
SCL line 0v

When only the charger is connected without the battery connected, the voltages return to 3.3v in both SDA and SCL.

It has already been tested with another battery and flex from another functional machine.

 

[2informaticos]

"When connecting the battery the voltage on ppbus_g3h is 12.28V."
What about charger alone?

Check diode mode to ground at SCL/SDA lines of battery bus.

 

[Mac Tech]

that's right, 12.28V

diode mode

SDA: 427
SCL: 427

With charger PPBUS_G3H it is 13.04V

SDA: 3.37V
SCL: 3.37V

When I connect the battery flex, the usb c meter restarts.

 

[2informaticos]

Check resistance over C7020/23 (ohm scale).
Also check SMC_DCIN/BMON_ISENSE levels.

 

[Mac Tech]

C7020 0.70M ohms on both sides

C7023 starts to drop from 02.23M ohms to 00.69M ohms then rises to 200K ohms.

SMC_DCIN_ISENSE 07.10M ohms

SMC_BMON_ISENSE 08.10 M ohms

 

[2informaticos]

I asked about resistance over the caps; in other words, measuring BETWEEN their pins!

Checking signal level, means its voltage...

 

[Mac Tech]

there is continuity between its lines.

C7020 voltages is 13.04v on both sides.

C7023 voltage is 14.77 on both sides.

 

[Mac Tech]

resolved. I noticed that ppbus_g3h with the battery connected went to fuse F7000, that was fine.

Analyzing the i2c lines of the battery I see that they feed on pp3v3_g3h.

This voltage comes out of ic U6990.

When I measure the input voltage which is PPVIN_G3H_P3V3G3H I see that there is no voltage.

This voltage comes from PPBUS_G3H which passes through a resistor R6905, which I measure and there is no PPBUS_G3H voltage, I see that the resistor is a little sulfated. I proceed to change it and find the solution.

Thnks!!! @2informaticos