Come to find out, many folks are having issues with the HP Photosmart C4200 and C4300 series printers with messages relating to “Incompatible Cartridges” “Missing Cartridges” “HP Print Cartridge(s) Incompatible or Missing”, so we found a work around to fix the issue.
If you cannot view the video, the follow steps allow the printer to print again.
Press the “Power” and “Cancel” buttons at the same time.
The screen should tell you to enter in a special combo key, and press the blue button, green button, then grey button.
Press the “grey” button to go down, until you get to the “Information Menu”, then press the green button to accept.
Then press the “grey” down button again untill you reach the “Checksum for relock data input” menu, and press the green ok button.
The screen should show a number generated, now simply back out by pressing cancel button 3 times.
We really hope this may help some folks who have this issue. It is a simple fix that may or may not help, and we are not associated with HP by any means. If you find any other solutions, please comment and share with others.