Printing Errors or Lights & Stuck Print Jobs

While printing, my 8620 showed one of the cartridges to be empty and needed replacement. I replaced the indicated cartridge which I knew to be low, and closed the ink door. The printer display screen then showed one of the other cartridges to be empty and I replaced it also knowing it also to be low. Closed the door and the displayed showed another cartridge that I had replaced a few days before to be empty. Thinking I may have received a faulty Genuine HP Cartridge from HP I replaced it also but upon closing the door I received the "printhead missing, failed, or improperly installed" message. Using the HP Support Trouble shooting procedures and trying each portion of the steps multiple times I arrived at the step that says the printhead has failed and I must buy a new one. Muttering under my breath, I ordered a new printhead from the HP Store for $120.00 plus 16.00 for expedited shipping plus approx 10.00 state sales tax. The printhead arrived in three days and I followed the installation steps found in the HP support pages (instructions in the package were the minimal "comic book" style of quick-install guides) and when I turned the printer on, the printhead failed or missing message was still there. I have tried removing and installing the head and cartridges multiple times.

While the display is showing the missing printhead message i can select the Ink Status icon and see the four cartridges showing completely empty with a big red X above each cartridge. Touching any of the cartridge icons, I see that the message "installed cartridge --951SETUP" and "supported cartridge HP951XL, HP951."

I have had the printer for two years and twenty days so the warranty appears to have expired. Does anyone have any suggestions as to additional steps I can try before I ditch the HP and try another brand?

Any helpful response will be appreciated.