As always with a malfunctioning device, Unless You have got there special setting, that took you a lot of time to configure, and it's a shame to loss, REINSTALL it.
The problem can be caused be many factors, and it doesn't worth the time to find which one is responsible for it.
If you would have given some more details I could have found you the specific driver for you. Since you didn't, this is the best I can do: http://www.hp.com/country/us/en/prodserv/printing_multifunction.html
You can find here the most updated driver that fits your system and install it.
I hope my reply will be useful.