I just connected the usb to my 30G ipod video and then went to connect it to the usb port. As I plugged it in, I saw a small spark and then realized that I plugged it in upside down. After connecting it properly, it will not turn on now. The battery is freshly charged and it turned on prior to the mistake. Another thing, the screen has a slight rainbow color in it now that is visable at an angle ( kind of like a calculater screen when you push on it) I'm not sure if the screen looked like this before but I'm concerned that I might have fried it. Is it time to replace it? The warranty just ran out.

go after the warranty replacement if it didn't expire too long ago less than 2 months. And dont settle for sorry your warranty is up. you will have to push it a little. I dont think you can plug a usb in upside down. It might go in but the connections don't match up. I see little sparks all the time with no adverse effects to my hardware.

try reseting your ipod first to see if that will help and then if it wont work go for the warrenty even if it expired they will probably give you a better deal then getting a new ipod from the store

travalon is correct in all cases. I would try Phantom07 advice first. The sparking may not mean much if it was small.