I've got 3 BL300 motors in xyz motion. Suddenly, after working just fine for months, I'm now getting a weird loss of power in the Y axis. This happens only when the spindle is running and only for the Y axis. The error is not generated with extremely slow jog speeds.

When the spindle is on and with very slow motor speed, even a slight touch on the motor axis generates external stop in Mach and stops the whole system, but VSD-A error leds are not lit. On higher speeds the axis advances just a mm or so and the halts.

What could be causing this? Perhaps a bad contact somewhere in the wiring? From where should I be looking for the reason for this.

I would appreciate a quick answers as I'm in the middle of a job that needs to be finished.

Thanks,
Risto