I was in the studio with my band i had forgotten the power cable of hd500 and i used another one which had 9volts and 3 amperes,while hd500 takes 9volts and 2,5 amperes minimum.since then when i connect the correct power cable a blank screen comes on,none of the switches works and it is not even recognized by the pc...please help me i have a gig in a few days and if i take it to vendor's store they will keep it...please!!!!i tried reseting the device with the directions on the d-pad but nothinh happened...can u suggest anything?