Upon turning the unit on it says "WAIT FOR USB CONNECTION". This message stays on. I can not turn the unit off. If I plug the USB cord in the unit, the screen turn purple and stays purple. I have used Philips Device Manager to repair the unit. It goes through the motions and then the message comes up that the unit is repaired. When I turn the unit back on, it flashed the same message that says wait for USB connection. Any help will highly be appreciated. Thanks