JcPenny Turntable/AM FM/Cassette/8 Track Player

[AE1924]

I am relatively new to this stuff and I am needing help.
I have a JcPenny 683-1790 that when you turn it on all you hear is one radio station playing. You can change source and move tuning knob and it has zero effect on the unit.
I started repairing unit due to cassette player needing belts replaced. The turntable, radio and 8 track all worked fine prior. I did not undo any wiring. All I did was unscrew board directly behind cassette deck to access belt better and screw it back it and ever since it has not worked right. The unit will play an 8 track and the cassette player will physically move but you get no audio. Attached are photos of the unit itself. I am unable to locate service manual. I can take more pictures if needed.

 

[toxcrusadr]

Sounds like the Source switch may be broken and permanently set on Tuner?

Turning the knob doesn't tune any stations? Either the tuning string is gone or there are serious problems in the tuner. I think I do see a tuner string behind the panel. I can't tell how the tuning is laid out from the pics but there should be an air variable condenser that moves when you spin the knob.

 

[AE1924]

The source switch was working previously with no issues and so was tuning knob. String looks good and is in tact. But no it will not change stations but does physically move back and forth. My boss seems to think the sound(radio station playing) is interference but I didn't have this issue when I first started working on it.

 

[illinoisteve]

You might have inadvertently "frustrated" a ground connection somewhere. That could cause a lot of problems.

 

[AE1924]

You might have inadvertently "frustrated" a ground connection somewhere. That could cause a lot of problems.

Is there a way you would suggest I could test for grounding issue? Like I said I am new to the electronic side of receivers. Mechanical issues is what I mainly handle