Try this
Remove both cartridges. See your printer's manual or help files for specific information on removing and inserting cartridges. Most HP printers must be turned on to remove the cartridges.
Unplug the printer.
Wipe the copper-colored electrical contacts with a clean, dry, lint-free cotton cloth.
If these dont work go to the following site
http://ipgweb.cce.hp.com/ipgna/calle...&lang=en&cc=us
It is an online chat with HP technician
Best of luck.