Printer Toolbox Not Recognizing New Black Ink Cartridge

1. Open the Printer Toolbox . There are two ways to do this:
   • Open HP Solution Center , select Settings , and then Printer Toolbox .
   • If the HP Solution Center method does not work, open Printers and Faxes in the Windows Control Panel, then right-click the printer icon and choose Printing Preferences . Click the Features tab, and then click the Printer Services button.
2. The Printer Toolbox opens. Click the Estimated Ink Level tab. A cartridge may be running out of ink even if the graphic shows otherwise. (see the note at the start of this section). Lines or streaks always appear in printouts when the cartridges begin to run out of ink. Replace print cartridges that are out of ink or low on ink.

you may have a bad print cartridge or it has gone bad...

I’m happy to assist further over the phone at https://www.6ya.com/expert/norman_d2fa496dce30c65d

hELLO THERE
there should be a section there for the maintenance of the cartridges and change cartridges make sure that you use this whenever you change out a cartridge cause if you use this when you change out the cartridge the printer will always show low on ink also you can reger to your users guide for further instructions on how to do this ok? hopethat this has been very helpfull dont forget to rate my solution
best regards mike
(USN) retired

To clean the HP Inkjet print cartridges from the HP Toolbox, using a Windows operating system, perform these steps:

1. Double-click the HP Toolbox icon on the computer screen.
2. Click the Printer Services tab.
3. Click Clean the print cartridges and follow the directions on the screen.

If the print quality improves after completing this sequence once, but the quality is still not quite good enough, repeat procedure. Start at Step 1, or click the Clean Again button on the final cleaning window. If this process does not improve the print quality, the HP Inkjet print cartridges might be low on ink. See the document that is provided with the black HP Inkjet print cartridge for instructions about how to use the ink level sensor to determine if the cartridge is low on ink. Replace the HP Inkjet print cartridges, if appropriate.

Please remove the cartridges from the printer. Take a dry lint free paper towel and gently wipe the contacts on the back of the cartridge (not the bottom from where ink is present). Wipe the contacts inside the printer (on cartridge carrier). Please snap the cartridges back into the cartridge carrier and please try to print a printer self test.

Dear friend, your Black Ink Cartridge is Empty thats why your printer is using the Colour Cartridge to produce the Black Colour. This is the reason you are having Dark Reddish Brown colour instead of Black.

Your printer doesnt support HP348 cartridge.
HP 99 Photo is the cartridge meant for 6940 which wud go in the slot for black cartridge. and you can print approx 130 photos .

My HP Deskjet 6940 is not printing. The color (left) low ink light is dark and the black (right) low ink light is flashing. I replaced the black ink cartridge with a new one but the low ink light continues to flash. No tears/rips in the circuit strip and all the copper leads appear to be connected

you need to print only in black if that is all the ink you have, and also you need to remove the color cartridge as it still registers in the printer as able to be used, although it is empty or near so. Did you remove the tape over the print head fron the new ink cartridge? Do a print head alignment, or use the toolbox icon to tell the printer that you just replaced the cartridge. Some HP models chip the ink cartridges so even a refill wont register as a full tank and the printer wont print. chip needs to be reset (difficult) or just replaced with a new cartridge.

The Deskjet 6940 will only show ink level for original HP cartrdgies. Refilled or reman cartridges will show as empty or unknown in the toolbox. This is not an issue with the driver, the cartrdige itself has information that it has been previously used and this is not resettable. You can continue to print with a cartrdige that has unknown ink levels, you will just not get low ink warnings.

Regards,
Bob Headrick, Micosoft MVP Printing/Imaging