Problem- The fuse just blew!?? driver or stepper?

[Marmot_Militia]

Mach3
PMDX-131
Geckodrive G201
been up and running for over a year.

Running some parts in plexiglass, no speed demon, or long runs, just cutting some circles. Had to run to the aid of my son, so I hit stop in mach3, clicked the E-stop external switch as usual, and was gone for over an hour.

Came back and the Z-axis fuse was blown. Looked at the wires on the back of the driver (as I traced which axis was not lighting up) and saw the insulation was a bit melted. Figured it shorted there. Cut, stripped, and remounted the wires, changed the fuse, plugged PMDX and transformer back in, and pop goes the fuse. Shut off power, took the wires out of the pin block to check for shorts in motor...then I realized I don't know how to check for shorts in motor. (Kelling stepper)

Don't know how to check if driver is bad either.

Any idea if leaving the power to the board on and just hitting the e-stop for an extended period will muck with the driver or is the stepper going to go kablooie first?

Thanks
MM

[chazmtu]

Hi MM,
Using E-stop should kill all signals to your motors and Gecko should have current reduction. The short probably caused your problem.
The motors are the easiest to check. How many wires does your motor have? 4?

Chuck

[Marmot_Militia]

Chuck,
There are four wires going from the Gecko to the motor but I think the motors have eight coming out of them. THey go one into two into the motor. I've not done anything to that end.

The z-axis sings even when the e-stop light on the BOB is on. Is this normal?

I checked the wires going to the motor and have two separate windings, but didn't check to motor frame. Also didn't pay a whole lot of attention to the actual ohm numbers.

Thanks,
MM

[chazmtu]

Yeah my motors sing when in E-stop too, thats the driver holding the motors still.
You can check your motors with a multimeter. Write down where the motor wires are connected. Your driver should have two coil symbols on them, disconnect the motor wires after the drive has been off for a few minutes (to let any power caps drain) and test resistance between ends of one coil. It should have a low resistance. Then try the second coil, it should be the same. Finally try testing between one wire from each coil and you should get no resistance the meter usually says "ol" or "overload". If you get any resistance between coils than you have a short in the motor. I would leave the remaining four wires connected to each other alone. Let me know what you get and we'll move on down the line.