12v12 dropping from DM and now not shown in device manager

I have 2 of the 12v12 on my windows 8 system. One shows up in device manager on com 4 and the other jumps in and out from com 6. Now the one that was on com 6 will not power up.

This morning I installed the drivers and software on another computer ( win 7 pro) and the Jrk (yellow led ) flashed for a second and windows stated it had a problem with the usb connected. So I uninstalled, rebooted and reinstalled, plugged in and no flash / power to JRK. I have tried different usb ports with the same results.


It sounds like one of your jrk 12v12 motor controllers is having a connection issues with the USB. Is the other one functioning correctly? Could you try using a different USB cable with the one that is not connecting? You might try using the cable from the one that is working. If that does not make a difference, can you try inspecting the USB port on the problematic jrk to see if you can spot any bent pins or anything suspicious?