Sansui 8080 tuner issue - second attempt

[Mico]

Hmmm..is it possible that my original thread from a few days ago got lost in the woods during site maintenance?
Just curious, and for sure no forum rule violations on my part.

 

[Mico]

Oh well, for sure it is gone and when I click on the old (saved) link I get something new from General discussions forums...
In any case back to the subject: on my freshly acquired 8080 FM Auto position does not give any sound even if reception is fine, however FM Dolby adaptor position works, other Selector positions work as well.
I looked at the wafer selector and it does not show (at lest obviously) any messing up from the third party. But I have read somewhere that some positions can fail because of switching dial lamps at the same time.
What, if anything, can be done about that?

 

[ranukic]

did you solve this issue?

what are the voltage readings at the demodulator IC when the unit is supposed to be producing sound but isn't?

 

[Robisme]

Turn off FM muting and see what happens.

Rob

 

[ranukic]

Thanks Rob,

FM muring has no effect to the humming. The only functional change to the system that changes the hum is mute and high filter. Changing the tone levels on the treble and mid but I don’t think those do anything more than muffle or raise the sound.

Any other ideas?

Thanks,
James

 

[Robisme]

I didn't think we were talking about a hum. Thought you no audio from FM?

Rob

 

[ranukic]

Sorry I thought this was a different thread.