I jailbroke my iPod using redsn0w and now it wont turn on?

I jailbroke my ipod touch 4th Generation 4.3.4 using redsn0w teathered jailbreak and the batterey died so i plugged it into my computer and nothing happened I opened Itunes to see if it would notice my device which it didn't and so I can't restore it so that it's back to normal please help me