PLC Death--Common Senerio?

My VPI PLC (Power Line Conditioner) seems to have gone on to the great beyond. This is the older model with the two dials for 33 and 45 rpm. With the motor plugged into the PLC it just locks up and vibrates back and forth in a very narrow arc...the motor does't turn full circle. Unplug the motor from the PLC and put it into a wall socket and all is well. Is this a common senerio. Is there a simple (cheap) fix or should I just toss the PLC and hunt down a used one?

Thanks for the input.