Problem with mine was (is) no grease!. There's nothing evident on the ballscrew and I can't tell if there is any in the ballnut itself. A lack of grease nipples and no way to install any, doesn't help.
I'll be wiring up the control box as per the diagram from
Homann Design. I got the various parts I needed from them (except the G540 which I already had). I especially like the 9 pin stepper
breakout boards with a built in variable resistor
I'll look up ger21's zero-screen set to see what it is
Still getting to grips with Mach 3.