About a year and a half ago my mill began having issues. The Z axis often would not respond. Playing with the printer cable would sometimes resolve this. At about that time I bought a Mikini mill for a large (for me) job. Using the same Mach3 software and the same printer cable the Mikini has worked flawlessly while the Taig sat idle.
I now have need for the Taig and now all 3 axis are unresponsive. They will intermittently 'hold' position when powered but will not move on command. The fuses in the MicroProto controller are good and the large capacitors have correct voltage.
I just emailed MicroProto about this but thought I'd present it to you guys.