I just fired up my Mach3 Gantry mill after it had been mothballed for two years.
In the interim I hooked it to a new computer.
I did a clean install of 3.042.020
I had to remember all the install problems I had and how to fix them.
I too could not get the motors to run.
Spent a day and a half.
Same problems as the thread.
Limit switches lit up the LED's and DRO's moved but no motor motion.
Then I went back through my PDMX122 board instructions.
It was the Charge Pump
I had not set it to pin17 port1
I activated it and Voila'
One other possible fix:
On my first installation years ago i remember deleting the parallel port from the device manager.
then on reboot when it found it again Mach3 had control of it.
Those are my two suggestions
