T-F1000 monitor Switch issue,need help.

[boilerplate]

Has anyone had a problem with the monitor switch causing a high pitch feedback when placed in source mode? When in the tape position a faint constant pitch can be heard between songs. I used cleaner and lubed the switch and the noise went away, but has returned.The switch works fine mechanically.
I am thinking that it is grounded internally somehow and replacing it would solve the problem.

After looking at the board diagrams I see that this switch is connected to many circuits in either Tape or Source mode. Having zero experience isolating electrical circuit problems I am stumped.Can anyone help? I am not sure if the switch is bad or the noise I here is an indication of a problem in one of the other circuits. Otherwise the deck sounds great when the volume is at a normal level Thanks:Boilerplate

[Skywavebe]

To start Boiler, what is a T-F1000?

Some of us seasoned Technicians may not have knowledge of what you are talking about at first. A picture of the unit might help.

[tapetech]

Might be a Pioneer CT-F1000 cassette deck. Just a guess.

Check your RCA cables. Deck Out should go to Monitor Input (not tape in). Input cables should go to Record Out of your amp. Not Preamp Out.

If cables ok. Clean all switches in the deck. Also, with the small upright circuit boards...check under the mother board for cracked solder joints for those boards.

[TWTRTECH]

Cleaning the record/play switch ass'y inside the unit should correct the problem.

[Pacific Stereo]

As TWtrtech says, I would be cleaning the two REC/PB switches.