Done lots of reading today and haven't found the solution yet. Here are my symptoms. When I powered up today, I got 3 constant flashing lights. Knowing the issue was likely an unplugged cable, I found the pan motor (external plug by the status lights) unplugged and plugged it in. Turned on the M5, got lights, they went out for initialization, then nothing. So I connected my tablet to see what was going on. Interesting that everything is working - status, compass, GPS, mode, drive and IMU are all good. The only issue I see is that my battery status is 0.0v. So I swapped batteries to a fresh one and same thing. Through my trouble shooting I discovered something interesting. I unplugged the pan motor, got a drive error, but immediately got the voltage to show as full power. Of course once I have a drive error I can't clear it till powered done and when it reboots it shows 0 volts again. Totally stumped... Any guesses?