820-01521 no audio on speakers

[Sr. Robot]

Hi, got an 820-01521 with no audio on speakers, no signs of damage.

The audio Jack works but not the internal speakers. Speakers show on OS and volume bar also shows.

Tired know working i/o board and flex cable, tried known working speakers.

I get 1.8v on AUD_PWR_EN. I also get PP1V8_G3S and ppbus on J6100.

PP1V8_S0_SPKRAMP_AVDD, PP1V8_G3S and PPBUS_G3H are present on U6400.

Replaced U6400 just in case, no change.

Diode mode to ground on J6620 seem good (all above 0.400)

 

[2informaticos]

Any history about fault appeareance?

Check diode mode at SPKRAMP_RESET_L and SPKRAMP_INT_L (J6100).

 

[Sr. Robot]

No history.

SPKRAMP_RESET_L = 0.001
SPKRAMP_INT_L = 0.360

removed U6400 and C6104. Still shorted.

 

[2informaticos]

SPKRAMP_RESET_L shorted with audio flex disconnected?
Then you have T2 internal damage; classic failure on this model.

 

[Sr. Robot]

Thank you.