Hi,

this unit has worked 4 years like a charm. Recently I have noticed that it does not hold set RPM under load even sometimes without a load. I mean, RPM set to 12k, actual speed varies from 11k to 12k (display reading), producing very nasty sound during cutting, with me praying not get any slower and breaking a router bit. Sometimes it works normal for 3 hours and then suddenly starts to behave weird for an hour and then works normaly again. Of course I did not touch the wiring neither VFD settings. RPM set by analog control.

Any idea on possible cause or what to look for? Dying capacitors?

Thank you.


Boris