820-01598 no power

[iremont]

Hey, first it came in no power, no sign of h20 or burn, i looked and
PPBUS_G3H = 0.3v and find problem with speaker amp. now i got

PPBUS_G3H = 12.3V
PP3v3_G3H = 3.3V
PP5V_G3S = 11.5V

seems like pp5vg3s got some problem, where to look and what next

 

[2informaticos]

Check diode mode to ground on the T2 lines connected to that chip.
Like SPKRAMP_RESET_L, SPKRAMP_INT_L, etc...

 

[iremont]

SPKRAMP_RESET_L diode mode to g 0.007v
SPKRAMP_INT_L diode mode to g 0.032v

 

[2informaticos]

So T2 internal damage.
Classic problem, when found corrosion underneath speaker amps; PPBUS_G3H connected there too.

 

[iremont]

Now i got 5v and 300mah but no 20v