When it comes to electronics, I prefer to buy brand new devices or gadgets. You would never know what was the previous owner doing and i guess the difference in prices won't be that much.

If you got a warranty paper, or the bill of purchase of that item and you think that it is still under warranty then you might give it a try and see if they can replace it. If not then you have nothing to do but to buy a new one as no one can fix this one here, sometimes if it's even a firmware upgrade and it get corrupted it would be difficult to repair and they will charge you a big amount to fix it.