I've got a Pioneer PL-707 turntable in pretty good condition. Was bought new way back when it came out and it's stayed in this family. It's been working fine ever since then except all of a sudden yesterday the motor started making a squeaking/grinding noise. It was working perfectly the day before, I turned it off when I went to bed at night and when I turned it on the next morning it had this noise.
I immediately thought it was the platter so I fiddled around a little with it, and the problem persisted. I even removed the platter altogether and the grinding remains. If the turntable is off and the platter is removed, when I turn the center spindle manually it makes the same noise. The grinding occurs throughout most of a full 360 degree rotation, but not all. For example, if you think of it like a clock, the grinding goes away from around 6 to 7.5/8 but starts right after that and ends again at 6 and continues in that fashion.
I have more or less isolated where the sound is coming from. When the turntable is in front facing me (the buttons are facing me and the tone arm is in its resting position in the upper right corner and pointing straight at me), the sound appears to be issuing from the upper left portion. Upper being the farther half.
Does anybody have any ideas as to what might be causing this sound or any suggestions for a solution?
I'd be much obliged. Thank you.