17MB130T , Vestel main board audio issue.Schematic & advice please

[zen]

Hi all .

Volume keeps being pulled to zero .

Removed toggle control & audio chip ( AD82587D ) , which is IC2 BUS controlled , but no change .

Also disconnected I/R Receiver .

Measured DC voltage on all pads where the audio chip lives ( see picture )

Only ones that differ from measurements on a working board , are pins 15 ( RA ) , 17 ( RB ) , 20 ( LB ) & 22 ( LA )

All at zero volts on faulty board , but that may be due to chip removed .

On fully working board , above pins all at 12 volts .

Headphone port also seems good .

[comptek]

Re: 17MB130T , Vestel main board audio issue.Schematic & advice please

Check components above and around the QR code as the place to the left is where the external button socket goes maybe be something there

[zen]

Re: 17MB130T , Vestel main board audio issue.Schematic & advice please

Thanks , will do .

Also forgot to mention that the silicon type heat sink pads under the PCB had leaked out slightly .

Washed the board down using IPA solvent , but there's is a possibility that the main CPU could have been damaged by the leak .

Hope not , as it would be game over , & would need to replace SSB .

[arizanotlari]

Re: 17MB130T , Vestel main board audio issue.Schematic & advice please

Hi.

remove r463 3V3 keyboard supply. if still volume goes 0 cpu is faulty.

Diagram : https://drive.google.com/open?id=1RE...I54Wnqnfp1MdhH

[zen]

Re: 17MB130T , Vestel main board audio issue.Schematic & advice please

Hello & thanks for reply. Carried out test , but fault persists .

Suspect the ARM manufactured CPU , most likely damaged by leakage .

Swapped out the board & all working , on test .