Dual CS5000 speed control problems

I have an otherwise mint and well-cared for Dual CS5000 with a Sumiko Blue Point that has a problem locking in at 33rpm.

I've tried swapping belts, cleaning, etc.

I can only imagine that this is the result of the chip or pcb for the speed controller being bad. If you're familiar with the CS5000, it won't drop the arm until the correct speed has been locked in. Sometimes I can get it to lock in by switching to 45rpm and back but this isn't really a good fix and sometimes takes minutes worth of trying.

Is there anyone that can fix this model out there or is familiar with this problem?

Mark