Geck 540 motor drivers??

[JAZZCNC]

I've used G540 and they are ok and very neat thing's but If your frying BOB's then something fundamentally wrong in the control box or machine wiring and changing to better drives won't stop anything. Plus Gecko's are not the strongest drives and you will fry them easy enough. I've killed x2 of the supposedly UN-killable 203V's and that was in normal router use not wiring error, the Only plus here is they do a good replacement warranty.

I wouldn't be connecting anything until you have gone thru the control box and machine wiring. All grounds back to same point (Star grounding) and all signal cables using shielded cables and shielded at one end only. Rout all cables carrying power in different trunking to signal and keep separate has much possible.

Your problem sounds more to do with signal interruption and noise/EMF than dodgy drives so I'd concentrate on improving this area.

Think about changing the PSU's to a single toroidal supply because the capacitors handle back EMF better, this would be my first component change if I couldn't find any wiring faults.
I'm no electrickery expert but have experience of similiar things and it could be high EMF getting introduced on the drive power line and because your using linear psu's they protect them selfs from returning currant. The drives will try to pass any extra currant back but if can't go anywhere they will protect them self and fault. (Or blow up if too high)
The caps in toroidal supply will absorb any EMF, either created by the motor/drives them self or outside influences, so they are much preferred for steppers anyway. . . . Also Very easy to build your own and if you want to go that route then PM me and I'll tell you whats needed or browse the forum there's plenty of debate to how it's done.!

If you really want change drives then I'd recommend going Digital and the AM882's are my preferred choice (thou never had them on Plasma yet)

Hope this helps and you get sorted quick.