820-01958 Air A2179 with power drain problem

[2informaticos]

Save data and do DFU restore.

 

[sekidata]

Already performed a DFU Revive but will try a Restore as well.

 

[sekidata]

No change after DFU Restore.
Another new observation: the right speaker does not work, even after trying several audio daughter boards, cables, and speakers.

 

[2informaticos]

Check diode mode to ground at SPKRAMP_RESET_L and SPKRAMP_INT_L.

 

[sekidata]

SPKRAMP_RESET_L: 0.40
SPKRAMP_INT_L: 0.005

Looks like SPKRAMP_INT_L is indeed shorted to ground (5Ω in resistance mode). This is a 1.8V line, correct? Inject 1.8V and see if the audio amp U6400 heats up?

 

[sekidata]

I removed U6400 and C6103 but the short persists (around 70Ω now). Voltage injection produces less than 0.1A current flow, so no heating up.
But I already know that the only component left is the T2 chip... internal damage probably keeps SPKRAMP_INT_L low which sends a continuous interrupt request which is responsible for the battery draining. Is my interpretation correct?

 

[2informaticos]

Yeah, T2 internal damage....