I know there are million post on "Losing Steps" so sorry for another, but I cant find how to properly trouble shoot my issue. My setup. MACH3 ,4 nema 34 motors, .Z, Y, X_A with A being slaved to the X (specs https://www.avidcnc.com/cdata/cad/sp...spec_sheet.pdf ) a Geckodrive G540 and a 120V power supply that outputs +48v 12.5A. Ok here is the problem, I bought this CNC used and the guy has ran it since 2014 with no known issues, but it has sat idle for about 2 years. When I run it after a long file it loses steps on the X axis motor.( the gantry gets out of square) I noticed it would randomly make a pop noise as when first powering up during the gcode running. Just to test it I switched the X motor cable with the slaved A motor cable at the Geckodriver board ( X cable in A port and A cable in X port, then switched dir in Mach motor setup ) and then the A motor would make a pop noise similar to when it powers up during running the g code. So the problem follows the driver and not the motor if that makes sense and its only on the A drive of the Gecko, all the others seem to be fine. Its like the A output on the gecko is having a small power interruption. The computer is the same one the guy has used since 2014 with no changes, and have I did read on another post that since it seems to be one issue that follows the A output and not other driver outputs, that its not highly likely a PC or Software issue. The guy I bought it from used it a lot and made custom doors for houses. Could this be a GeckoDriver or a power supply problem? How do I trouble shoot either one? Any advice on what to check? Thanks in Advance