Marantz crs-4803s electric noise problem

[boomboomboom]

Hi bro,,, I have a Superscope Marantz crs-4803s.
If you turn on the power without pressing any button, you can hear the electric noise,,,
However, if you press the external input button, fm button, mechanism (casset player) button, the electrical noise disappears,,
I don't know what the problem is, bro,,,

 

[Superduper]

The switches and controls have oxidation, which needs to be cleaned. Use electrical cleaner spray or similar. You may have to dismantle boombox to clean thoroughly though.

 

[hopey]

Sounds like a ground loop, is it still there when you select tape and turn it up real loud?

 

[boomboomboom]

Sounds like a ground loop, is it still there when you select tape and turn it up real loud?

No, only when I turn it on and the tape and radio work normally, no electrical noise, just a little white noise

 

[Netsurfer_x1]

This sounds like a case for breaking out the De-Oxit & giving the switchgear a good spray out & cycling.

 

[hopey]

It sounds like there is no problem. Once you put load on the rail the ground loop is bypassing the noisy cap.