I would like to know also. Mine has done the exact same thing. UMX says they can do nothing but send a new one. It was on lock screen and doing absolutely nothing but lock screen activated. No buttons no functions worked. UMX tried resetting, erased everything then when they got ready to program new settings it went to screen you're talking about and wont do anything. Wont turn on or off, no volume, NOTHING works. 

Did you call UMX and tell them. I did and they are sending new one free of charge. Did you ever get any answer from anyone what to do?