Ipod=blanck screen :(

Hi. I left my ipod nano on my speakers for 2 mins and then when i got back they where making a wierd buzzing sound and the screen was black. i tried to charge my ipod cos it was on low battery and the computer isn't recognising it. I've updated itunes, held down the middle and menu button lots and i've tested the cable and hte cable works for my dad's ipod. it is also not being recognised by my computer so there is nothing in the devices with removable storage bit. :'(

PLEASE HELP ME!!!