Well if it does reset then you know it's electrical so you've eliminated mechanical.!!

RE noise: Ok lets take a look at the motor tuning settings.? In Mach goto Config/motortuning/ then at right hand side click on each Axis individually and tell us what it says in the "Steps per" "velocity" & " acceleration" boxs.
You must click on each individual Axis button to see it's individual setting and if you change any settings always push enter and save before moving to next Axis.