Recently purchased an early 80s vintage JVC integrated amp. Very nice looking, but apparently had never been opened/cleaned during its life, very, very dusty. Upon initial power up, amp would shut down after about 5 seconds, everytime.
Went ahead and cleaned her out with compressed air and brushes. On one blast a small metal pin from a watch band flew out... Ahah! Theres my short... and when I powered her up after dusting, it played perfectly with the matching JVC tuner. That is until I started tuning down lower on the dial. Beyond half way, static, clicks and loud pops, and the amp would shut down.
Okay, now I'm thinking I have a tuner problem. Crack that open and clean it, but it is already very clean since as it is a sealed cabinet. Power up again and no change. Decide to use Deoxit 5 contact cleaner on all the amps pots and switches as recommended by folks on the Audiokarma forum. Only pots I did not spray where the speaker selector and balance adj since they are sealed.
Now when I power up, the amp instantly has dancing meters and pops, shutting down again and again. Even with a different source or no source at all, things have gotten worse with the cleaning. Turning dials and throwing switches, does not eliminate or increase the noise. The problem stays the same.
I now need assistance with where to go next. Is there some kind of amp troubleshooting decision tree that I can follow to isolate THE source of the problem? I see no visible signs of overheating, corosion or leaking caps. Do I open up all the pots and clean them by hand?
Tired of cleaning everything without knowing the source of the problem, as I am likely to make things worse... Ooops, too late I already have!
TIA,
Junior
Audiokarma member newbie and now a newbie over here!
Went ahead and cleaned her out with compressed air and brushes. On one blast a small metal pin from a watch band flew out... Ahah! Theres my short... and when I powered her up after dusting, it played perfectly with the matching JVC tuner. That is until I started tuning down lower on the dial. Beyond half way, static, clicks and loud pops, and the amp would shut down.
Okay, now I'm thinking I have a tuner problem. Crack that open and clean it, but it is already very clean since as it is a sealed cabinet. Power up again and no change. Decide to use Deoxit 5 contact cleaner on all the amps pots and switches as recommended by folks on the Audiokarma forum. Only pots I did not spray where the speaker selector and balance adj since they are sealed.
Now when I power up, the amp instantly has dancing meters and pops, shutting down again and again. Even with a different source or no source at all, things have gotten worse with the cleaning. Turning dials and throwing switches, does not eliminate or increase the noise. The problem stays the same.
I now need assistance with where to go next. Is there some kind of amp troubleshooting decision tree that I can follow to isolate THE source of the problem? I see no visible signs of overheating, corosion or leaking caps. Do I open up all the pots and clean them by hand?
Tired of cleaning everything without knowing the source of the problem, as I am likely to make things worse... Ooops, too late I already have!
TIA,
Junior
Audiokarma member newbie and now a newbie over here!