I am trying to bench run an FET-4 kit from Stepperworld. I start the the software (Mach-2 or 3) then turn on the power supply to the FET-4 and the motors seem to run erratically even with out an NC file loaded. Aren't they supposed to make a nice smooth hum when they run?

If I cycle the power to the FET-4 sometimes they don't always run. Why are they not quiet and in control?

Thanks,
Rob

There is probably noise on the step line or the PPort is 3.3volt instead of 5volt.  Are you using a breakout board or direct to the pc port?

Turns out the power supply was bad. I have the steppers mounted to the X-Y table now but can't get MACH-3 to move anything. I can get steppers to move if I use VBSTEPDIR4XP.EXE from Stepperworld.
The OS is windows2000, instead of XP. Will this be a problem?

Thanks