iPod Video Screen Flickering

I found one of my family member's old Firewire to 30-pin charger. I heard that it was faster than the USB to 30-pin, so I plugged the ipod in and it showed the apple logo boot screen, but it just stayed there, then a few minutes later I touched the click wheel and it was pretty hot. So I unplugged it and I let it cool down, then I tried plugging it in to my computer and the ipod screen started flickering.

What do you think the issue could be.