A couple of suggestions:

Make sure cupsd is running. Open a terminal and type: ps -A , if it doesn't show up start it by typing: cupsd.

The PSC 210 sometimes needs to be unplugged, both usb and power to reset itself, I don't know why but I had the same problem. It might be a good idea to completely reboot the system. You should see references to the HP drivers as the booting progresses, or check dmesg output. And try deleting and reinstalling the printer - again - I had to do this but it has worked since.

HTH