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It can hum, screech and vibrate in many different ways and most often when winding/rewinding.
Common fault is dried lubricants in the tape reels where they sit on each their steel pin.
Getting in there is not for the faint-hearted. There are different ways in including several springs,
brakes, screws and brackets but it can be done.
Cleaning and adding fresh silicone grease will normally cure it.
In rare cases, when operated for a long time with the fault, a tape reel (plastic) can be worn
enough to require replacement.
Martin