Stepper motor makes chirp noise after jog, then g540 faults

[ger21]

Perhaps some bad ground loop in your electrical system?

Try plugging everything in to a different electrical circuit.

[QuinnSjoblom]

Perhaps some bad ground loop in your electrical system?

Try plugging everything in to a different electrical circuit.

Do you mean a different ac source? The 2 different computers I tried are in different rooms on different circuits. In both cases the computer and power supply were on the same circuit. Should I try putting them on separate circuits? That just creates a ground loop right?
As for the dc wiring, all I had hooked up was a single positive and negative from power supply to g540 and 1 to 4 motors plugged in. Tried with just a loop from 10 to 12 for e stop, also tried putting g540 and power supply into its sheet metal enclosure with actual e stop wired up, also tried with motors bolted to machine.

I don't fully understand how ground loops work, but what if I use a power inverter hooked to a battery to power my computer, then power the g540 power supply from the wall? Would that eliminate a ground loop that I may or may not have? I have an inverter if you think that's worth trying

[QuinnSjoblom]

Well, whether or not it's relevant, I tried plugging the power supply into my inverter/battery so that the computer and g540 are only grounded together through the usb. Made no difference.

[SatanKlawz]

Are there any updates to this problem? I bought my G540 about 3 years ago (REV 8) and just today got it plugged in testing. I have the EXACT same chirping issue and white noise. I have tried all of the settings described above including speeds and trim pot. I have even plugged the stepper straight into the g540 and there is zero change.

My setup is identical with a genuine UC100 (not a knockoff). Ideas?