Hp 7500a "The following ink cartridges appear to be missing or damaged"

SOURCE: Receiving the message

The message you are getting may be due to the following reasons :

1) Cause : One or more ink cartridges missing.
Solution : Remove and reinsert the ink cartriges and verify that they are fully inserted and locked in place.

2) Cause : One or more of the ink cartriges are not installed or are installed incorrectly.
Solution : Remove and reinsert the ink cartriges and verify that they are fully inserted and locked in place. If the problem persists, clean the copper-colored contacts of the ink cartriges.

SOURCE: HP psc 1350 HP 57 print cartridge

Same problem with me.
So:
I openede the whole box ( 4 screws ) in the corners. Then I presed the tiny belt on the left side to its socket, cleaned the contacts of the cartridges (56,57) with water and made them dry.

Then I reched the position of the small door which is ment to be opened once you wnat to replace the cartridge.

After this the printer works again.

SOURCE: Ink Cartridges

If is an original brand? Some generic cartridges or refill ones gave that problem.

SOURCE: ink cartridge problem! The following ink cartridges appear to be missing or damaged.

Solution :
1. clean the ink cartridge contacts both in the printer and the cartridge with a lint free cloth or a cotton swab. and try inserting the ink cartridges again. if it wont work proceed to step 2.
2. unplug the power cord at the back of the printer
3. press and hold # and 3 keys at the same time and plug the power cord back in. Do not release the two keys. wait until the printer would say "partial nvram reset" or anything that says "reset". if this still would not resolve the problem
4. do the same process as 2 & 3 but instead of # and 3 try # and 6. instead of saying "partial nvram reset" it should say "semi-full nvram reset". and if it would not work better go to an onsite technician. but if your printer if brand new return it to the retailer and exchange it. but before you do that try calling HP technician they would instruct you to the things i have given you. Just tell them what you have had done and asked them to replace the ink cartridges. This are the informations the agent would ask you about the ink cartridge
part number and also the expiration date.
try to ask for a replacement first if it would not resolve it. then go to a technician. I could not assure you that a technician could fix it because i have troubleshoot this kind of problems and there are alot of printer parts that needs to be fixed. Usually i suggest my clients to buy a new printer instead

SOURCE: HP L7680 the following ink cartidge(s) is missing or damaged

I have the same problem, but only with an original HP OEM cartridge that replaces the generic (which worked fine but is empty- if I put it in the error goes away- but can
t print because it is empty)