I have a 4 axis board that just quit working.??
I purchased a 4 axis kit with 425's from Jeff a couple of years ago and have hooked it up to a small mill. It has worked great and have had no issues with it at all. I have about 20 hrs use on my machine now. Last night I was running a program as normal and the xylotex unit shut down. The light was on in the switch because it was getting AC but the power supply shut down. I disconnected the AC took the box apart right away and nothing was hot, no trace smells of smoke and nothing looks burnt on the driver board. I disconnected 24v Vbb from the driver board, hooked up AC, turned the box on and the power supply and the fans came on.The P.S is putting out 28 v. I test across Vbb and GND in on the board with it disconnected and it is shorted out. I also tried this with the motors disconnected from the driver board and it was still shorted out. If I hook up 24 vdc to Vbb again P.S shuts off again. What is the normal cause of this happening and is there a fix other than buying a new board? The system was under low load meaning the steppers weren't being worked very hard at the time it quit and the xylotex system has very low hours on it. Oh what could it be ??

Kel1