i have a unlocked motorola razr maxx hd and i have had no problems with it until now. battery was dead so i charged it, and the M sign comes on.. usually than i waited for it to charged until 5% and i turned it on..but it wouldn't turn on.. the M sign showed up and than just closed. i've charged it for a whoe 6 hours and nothing!!!! i tried to press down on the power button n down volume key but nothing!! please help!