Hey ,
I am using Gecko 540, I had everything set up and running on my Kitchen table...was running fine...checked it today before moving everything to my machine and it has gone crazy.....I rechecked all the settings and could get no movement on the X axis...but the Gecko is in fault and I can't get it out...I have unhooked everything except the power supply and the Estop and powered it up and it is still in fault...Help.

The G540 expects a chargepump signal from Mach. If it does not see that signal the fault light will not go out. You can bypass the charge pump function with the switch on the G540 marked 'Chargepump'.