Hello, yesterday, I received a 1981 Panasonic RX-5150 boombox in the mail, and it has some problems. The first problem is after installing a new belt, I notice that I can hear a very loud "shuffling" sound--which is the belt moving around. I assume it or the drive wheel is not on there tight enough.

The bigger problem, however, is when I leave the boombox sitting for a period of time, when I go to turn it on--to any setting--I can hear static and when I turn the volume up to a certain point, a very loud, very high-pitched sound will emit from the speakers. This will stop after a minute or two of use. The tapes also sound quite muffled, and I've cleaned the heads and rollers accordingly.

Anybody have any possible answers? I would love to keep this boombox and not have to send it back.

As with all collections you should have on hand contact spray and demagnetizer. Spray your knobs and demagnetize the heads. Hopefully this will help.

Sometimes a belt change needs more than a new belt.  If idle for long periods the rubber contact tyres (if this one has them) get dry with flat parts where they've sat in the same position for a long time.  Alternatively a good lube around pivot points can help.

I have sprayed all the contacts out and cleaned the head. The head may need a slight adjustment, as my much smaller Panasonic RX-4955 did. As for a demagnetizing device, I do need to get one.