In article ,
David Naylor wrote:

Sounds to me like a cap has gone south, Are there any caps that have
vented or buffy looking. check out the power supply caps, thats the
usual cause of slow motors othe than the motor it self

I had a look at all the caps - I've replaced caps before to deal with problems in older gear. This unit is probably only six years old so it'd have to be a defect rather than normal aging.

I might check to see if there's a ripple AC voltage on top of the motor voltages - that should tell me if it's a cap, correct?

Thanks for your advice!

MK.