820-00138 A1398 2015 - Not turning on when battery is connected

[Saurabh]

- With the battery disconnected, the device turns on with direct power and works perfectly fine.
- Connected the battery while the machine is on. Battery being detected and charging fine.
- Device won't turn on with the battery connected. Same behaviour with known good battery and minimal components connected to MLB.
- Inspected MLB under the microscope. Clean.

Not sure where to start. Please help me.

 

[Saurabh]

F7140:
With battery, charger connected - 12.32V
With battery, no charger - 11.67V
Without battery, charger connected - 12.61V
Without battery, no charger - Hovering around 1.5-1.4V.

U7100:
Resistance B/W 17/18 Without charger - 2.8 ohms
Resistance B/W 17/18 with charger - 2.649 Mega ohms

Resistance B/W 27/28 Without charger - 21.8 ohms
Resistance B/W 27/28 with charger - 21.2 ohms

 

[2informaticos]

With both battery and charger connected, board doesn't turn on pressing power button?
Check if SMC_ONOFF_L drops when pressing the button.
If not, use R5115/16 pads, instead of battery bus.

Any history available, liquid signs?