The lid to my hp 3310 is stuck open.

Check back by the hinges there should be a catch that locks the lid up just release the catch. If yours does not have this check to make sure you don't have to lift up again to release the lid. These are the only problems with that type of printer that I've seen, I hope this helps if not let me know and I'll do some research and try to find an answer for you. Good luck.