Panasonic without sound
 

I have 2 pices of Panasonic NV-HS950-players. Superb machines, just to say that :-)
But now one of these has decided to not play any sound. I have tried many tapes, same result, those have sound on the other. I even had to retake about 14-15 tapes because of this, but thats a part of the game.
And because there are about noone in Norway that can fix these old players i have to ask.
Symptons piro to this was that sound was gone in some parts of the film, then i got a summing sound, just like ground-faulst in soundsystems.
I have tried to clean the heads with isopropanol/spirit/alcohol, no change. Oh, one change: the picture got a little better :-) :-)
But now i am stucked, where to start finding faults? I have been looking for bad capasitors, but didnt find any...
Help?

We don't know your level of electronic repair .
Is the no audio coming out of the audio jack or rf tv antenna jack?
If it has both did u check audio on both?
Is the tape tracking on the audio head ok?

There are no sound out from any place, and there are no indication on the display, where the meter for the sound is. No reaction there.

There are two audio tracks in these machines, the linear track and the stereo hifi tracks. Can you switch between these?

If there is no audio on any track maybe the white and red audio output sockets have been damaged so that the internal connection has been broken.

Try wiggling the connector to the head while playing.
Possible a crack circuit board.
Do a very good visual.
Possible capacitors, usually swells, or leak our of bottom.
Some small caps may not show any symptoms.
Maybe component may work by heating.
Try hair dryer. Don't get too much heat.
Usually I try heat and freeze mist to see if I can get components to act up.
Look at data on ics see if any have audio in or out ,use signal generator
And or scope to troubleshoot.