RC-838 Problems but maybe not what you think

[Biphonic]

Back in the 70s when my dad first came to the US he bought a JVC RC-838JWII and when I was in high school about 8 years ago I used to carry the thing with me wherever I went. He and I both seem to have very fond memories of thing.

I recently put some batteries back in it to see how its faring after all this time and was distressed to find some odd things happening. Im hoping I can get your guys help in diagnosing the problem, I'm gonna just put all the investigating I've done and hope that some of it is useful:

• When I'm using the Phono input with my turntable
  • Mono - Works
  • Stereo - mostly works, right channel is a little quieter
  • Expand - right channel is quieter and a little distorted
  • Biphonic - right channel is quieter and a little distorted

• When using the Radio
  • Mono - mostly works, left channel is a little quieter
  • Stereo - right channel is much quieter
  • Expand - right channel is much quieter
  • Biphonic - right channel is much quieter

• When using the Line in connected to my phone
  • Mono - mostly works, left channel is a little quieter
  • Stereo - the right channel is completely non functional just static and weird echos
  • Expand - distorts left channel same right channel as stereo
  • Biphonic - distorts left channel same right channel as stereo

• I would test tape, but to be completely honest if I can get the other stuff working I don't think I care too much.

The weirdest part (to me at least) is that everything I wrote above is reflected when I am using an external output like headphones. I tried taking off the back to see what was going on with it but since there are wires soldered to the back panel I didn't get very far other than seeing a quick look under the hood.

Any ideas whats going on with this thing? I was originally thinking of replacing the speakers but now I'm hesitant to mess with it too much. Do you guys think its the switches like I've seen some people complain about in other threads?

Any suggestions where I can get it fixed or some resources so I can try and fix it myself?

Literally any help at all will be greatly appreciated, I really want to get this thing working and do my best to keep it working for another 40 years so any guidance would be super appreciated.

 

[DPaignall]

Great question, answered by a common reply here - 'Clean the record bar'.
The record bar is where most signals are passed through to the tape recorder.
Even though the tape recorder feature is not needed the signals are still wired to pass through to it.
It is an electro-mechanical interface prone to corrosion and dirt.
To clean the record bar you will need to take the unit apart until you can get electrical contact cleaner sprayed into the bar.
The bar will look something like the one below, bar shape, near centre, lots of wires attached, it's moved by the the record button.
Switch the bar up and down repeatedly whilst spraying, repeat several times.

 

[TW5]

The record bar switch can cause many problems
but dont put a cassette in it while cleaning or the cassette will get erased.

 

[hopey]

It sounds promising I would attend to the potentiometer's. Try cleaning with contact cleaner or Alcohol.

 

[Biphonic]

Thanks for all the help! just to make sure I am looking at the right thing, is this the record bar in this image??

 

[DPaignall]

Yes that's a record bar, yours may be elsewhere but will similar looking.