C4780 printer, I placed an incorrect cartridge in & then removed it & placed the correct cartridge

[chuck650]

C4780 printer, I placed an incorrect cartridge in & then removed it & placed the correct cartridgebut the printer thinks I still have the incorrect cartridge in the slot, when I've got the original correct cartridge in the slot. How do I re-program the printer to accept the original cartridge now?

[Raj1788]

@chuck650

Welcome to the HP Community

I suggest you do a Hard Reset on the printer

(1) Turn the printer on, if it is not already on.

(2) Wait until the printer is idle and silent before you continue.

(3) With the printer turned on, disconnect the power cord from the rear of the printer.

(4) Unplug the power cord from the wall outlet.

(5) Wait at least 60 seconds.

(6) Plug the power cord back into the wall outlet.

NOTE: HP recommends connecting the printer power cord directly to the wall outlet.

(7) Reconnect the power cord to the rear of the printer.

(8) 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.

Clean the cartridge and carriage electrical contacts

1. Gather the following materials:

   • Distilled water (tap water might contain contaminants that can damage the cartridge)

   • Cotton swabs, coffee filters, or other soft, lint-free material that will not stick to the electrical contacts

   • A clean sheet of paper

2. Open the cartridge access door. The carriage moves to the center of the printer.

   Figure : Open the cartridge access door

   

3. Wait until the carriage is idle and silent, and then disconnect the power cord from the back of the printer.

4. Press down on the cartridge to release it, and then pull it toward you out of the slot.

      CAUTION: 

   Do not leave the cartridges outside of the printer for more than 30 minutes. If the cartridge is outside of the printer for too long, the ink can dry and clog the nozzles.

   Figure : Remove the cartridge

   1. The tri-color cartridge is on the left side of the carriage

   2. The black cartridge is on the right side of the carriage

5. Inspect the cartridge contacts for ink and debris buildup.

6. Dip a clean swab or lint-free material into distilled water, and then squeeze any excess water from it.

7. Hold the cartridge by its sides, and then clean only the copper-colored contacts.

      CAUTION: 

   Do not touch or clean the ink nozzles. Doing so can result in clogs, ink failure, and bad electrical connections.

   Figure : Clean the cartridge contacts

   1. Copper-colored contacts

   2. Ink nozzles (do not touch or clean)

8. Repeat these steps for the other cartridge.

9. Clean the contacts in the print carriage, located inside the printer.

   Figure : Print carriage contacts

   

10. Wait 10 minutes to allow the cartridge and carriage electrical contacts to dry.

11. Hold the cartridge with the HP logo on top, and then insert the cartridge back into the carriage slot. Push the cartridge firmly into the slot until it snaps into place.

    Figure : Insert the cartridge into the carriage

    

    • The tricolor cartridge goes into the left carriage slot.

    • The black cartridge goes into the right carriage slot.

12. Close the cartridge access door.

    Figure : Close the cartridge access door

    

13. Reconnect the power cord to the back of the printer.

14. Press the Power button to turn on the printer.

15. Try to print a page.

Keep me posted, how it goes!

If the information I've provided was helpful, give us some reinforcement by clicking the Accepted Solution and Kudos buttons, that'll help us and others see that we've got the answers!

Have a great day!

Cheers:)