Chosen Solution

Cleaned and reset print cartridges and printhead; checked physical gear issues for carriage; checked for paper jams. No other obvious answers present themselves.

try these steps Have you tried to clean the cartridge contacts as well as the rollers?Are you able to move the carriage manually?Did you perform a hard reset on the printer? While you respond to that, here’s what you need to do: In some cases, removing the ink cartridges and resetting the printer can clear the error message. Turn on the printer.Wait until the printer is idle and silent before you continue.Disconnect the USB cable from the rear of the printer. If your printer has a network or wireless connection, leave it connected.Remove the ink cartridges from the printer.With the printer turned on, disconnect the power cord from the rear of the printer and from the wall outlet or power strip.Wait at least 60 seconds.Plug the power cord back into the wall outlet.Reconnect the power cord to the rear of the printer.Turn on the printer, if it does not automatically turn on.The printer might go through a warm-up period. The printer lights might flash, and the carriage might move.Wait until the warm-up period finishes and your printer is idle and silent before you proceed.Reinsert the ink cartridges, and then close the ink cartridge access door.If you receive a prompt to print a calibration page, do so.If you disconnected the USB cable, reconnect it to the rear of the printer.Try to print.from here

When I open the ink cartridge lid , the ink cartridges do not move to an accessible position.

I was having the same problems with my HP 6600 last year. Tried everything and even considered replacing the entire print head. Ultimately the solution was to replace the HP with a Brother J5330DW.