So one minute your printer is working fine and the next you have no black printing...what has happened?
I ran short of ink in the Black cartridge but did ot replace it straight away..........then bought 2 new black cartridges......and the printer refused to print anything Black!! My printer is the Photosmart 5155 and as far as I know there are 2 printer heads. One for the colours and one for Black. It also appears the printer heads are not accessible or serviceable.
So what is the cause of the problem. Clearly no ink is getting to and/or being delivered by the print head and there are 3 possible causes
1. The cartridge is empty....easy to fix!
2. The cartridge has an obstructed vent......thats the T shaped mark on the top of the cartridge as you look at it installed in the printer. When you remove the wrapper on a new cartridge, that T is supposed to exposed. If it is not ink cannot fall from the cartridge onto the pad on the base of the cartridge. Clear it away with a pin. simple to do.
3. If....as is most likely, neither of the above are the reason for the failure, the fact that no ink is getting to the printhead probably means that dried ink is causing a blockage. That blockage can either be on the gauze or the delivery tube below it to the printhead. If you remove the cartridge you will see the gauze. It is the area that the felt pad on the bottom of the cartridge engages with. A good way to check if dried ink is your problem is to look at the little gauze sections relevant to each cartridge. If ink is flowing those gauze sections will be stained with the relevant colour. If it looks clean....bingo.....So here is how to get rid of the dried ink.
Use hot water and an artists brush. Stipple the gauze with the wetted brush repeatedly. Use an absorbant tissue occasionally to soak up the moisture but do not rub. If the dried ink problem extends to the area below the gauze this treatment will not fix you problem straight away. You need to leave the printer with the ( new) cartridge installed for 12 hours. The water you have applied through the gauze will then have had time to work on the ink delivery channel below the gauze.
When you re check the printer after 12 hours or so, remove the cartridge and see if the gauze now looks like it has black ink on it ( rather than just looking clean)....if it does your printer should now work. If not, repeat the process.