funny enough i was playing with machine for a few months before my small cnc came available and the lights kept flashing overload....the only way to reset was to switch off the supply and back on...being a cold shed and sudden changes in state for the drive..i assumed the voltage spikes...i work in the electrical industry so should of known that..my own mistake...took drive apart and it looks like a wired resistor blew so might play with that at a later date..hopefully resurrect it...the pictures show the 6040 cnc i won on ebay and the drives which up to now have been faultless, but i do have a selection of new drives available if these fail as predicted on most forums...
The motors were pre wired on my kitchen table before the move into cold shed so i do believe you are correct in the voltage spike syndrome...friday afternoon im too busy on the beer to but have been known to play in my shed under the influence...
But as you said cnc is to much fun to be easy...love the stuff.
Cheers Skiprat