Minirambo - Y axis quit working

Now that robotics season is over I have gotten back to working with my MPCNC. It was working fine until one day the Y axis quit working. I am sure that it is the channel on the Minirambo board because if I swap the stepper motor wires the other other set of motors work just fine. I was able to go into the arduino configuration files and change the E Motor output and the Y motor output pin assignments and wire up the Y axis motors to the E channel. Now things are working fine again. Any ideas what may have gone wrong? Anything else I should be concerned about?

 

 

The only thing I can think of might have been a full disconnection while the drivers were fully powered. That is the only thing I have not seen tested, any other way to kill a driver has been prevented with this board. Or possibly a metal chip shorted it?