What was you're code commanding the Axon to do? And was it commanded to output data to USB?
Also, measure the voltage of your battery for me.
Lastly, on the USB connector you will see 5 little pins coming out the back of it. Get out a fine tip soldering iron, turn it up to max heat, and reheat the solder on each pin. Be careful not to create any solder bridges. There is a chance that maybe a pin came loose.