Well i would like to certainly thank the Geckodrives Motor Control for taking the trouble to inspect my broken drives. Recieved with thanks!

In the invoice I was provided with inspection results, in 3 of the G230V D, it reads "Customer-induced damage by possibly applying excessive voltage on logic inputs was found." But with heartiest condolence, Geckodrive is nice to provide one replacement drive! Thanks again

I would like to certainly understand more about this damage, as I truly have not applied excessive voltage to the step and direction pins. The step, direction and COMMON GROUND pins are purely from the parallel port of the PC.

How may excessive voltage occurs? Are the causes are by high frequency noise, or EMI?

How may one prevent such from happening? Is there a suggested circuit I can construct to prevent such excessive voltage?