The board is a micro clone. When new it shows up in the IDE as Genuino Micro.
I can't remember exactly what I did, but I now have two of these not working. In Win7 device manager they are unknown device. The RX LED is on solid.
With the first one that got screwed up. I was loading a sketch I haven't used before. And I'm not sure if board was set to Genuino or Leonardo.
Pretty sure on the 2nd one I uploaded the same sketch with board set to Leonardo. That got screwed too.
3rd time. An old trusted sketch. Board set to Genuino. All OK.
So my questions are:
Can I reset/save my boards? If I can then I can experiment to answer my other questions.
Did having the board set wrong, cause this problem?
Can a bad sketch cause this sort of problem? I can upload the sketch if that a possible cause. I noticed that the code tries to index into a structure that's not big enough.