JVC turntable speed problem

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My JVC turntable suddenly has problems keeping the right speed. It plays a little bit too fast, and the speed wavers a bit. It worked fine a week ago, but now it's suddenly got this issue.

It's belt-driven, though I don't think it's a belt problem because it seems to me like that a belt problem would make it too slow rather than too fast.

I know just enough about electronics to be deadly, but I don't really know much about the workings of a turntable. I know it's got a DC servo motor, so I'm wondering if a voltage regulator chip went, and it's supplying slightly too high a voltage to the motor. If this is the case, would it be a simple matter to find the faulty chip and switch it out? If not, then does anybody have any ideas?

Thanks for any help.
 
Sometimes this problem can be caused by a speed adjustment pot, either connected to an adjustment knob on the panel, in those thus equipped, or inside the unit on the circuit board.

Just like a volume pot, they can go bad. The difference is that they aren't moved regularly to buff off any corrosion on the pot wiper contact point.

If you find an adjustment pot, just moving it back and forth a few times then adjusting the speed with a strobe disc might just work. A product called Faderlube is also a good thing to use on pots. If it's a common type, a replacement might be better, though, and cheaper than Faderlube!

I don't know JVC turntables, but this is a possibility...

Stuey
 
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