print quality diagnostic black colour block is white

[CatEde]

I have run all of the cleaning options, print head alignment, print quality diagnostic etc but cannot get the printer to print out any emails and essays. I have also tried a manual clean that was linked on one of the HP sites.

Bizarrely the text on the print quality diagnostic shows up in black ink but the black colour block is completely white and the  printer lines and cross at the bottom of that page are incredibly faint.

What should I do next?

Your help is much appreciated.

[Bob_Headrick]

The troubleshooting steps in the document here may help resolve black not printing on your Photosmart 5520. 

Note that the diagnostic pages use a mixture of black and color inks to print the outline and text areas.  This is done so the information can be read even if black or one or more colors are not printing properly.  While it may appear this page is printing black it is actually a mixture of colors you are seeing.  You can force similar results by selecting Photo paper in the driver settings.  Since the pigmented black ink is not compatible with glossy photo paper the printer will sue the color inks even to print black text if photo paper is selected.

If the standard troubleshooting did not resolve black not printing I would suggest removing the black cartridge.  Turn it over and examine the area around the ink port.  There are four orange plastic spots, left over from the protective cap.  Make sure these are flush with the cartridge body, if not carefully trim them flush.  If the plastic nubs protrude they can prevent the cartridge from seating properly.  Before replacing the cartridge in the printer dribble a few (maybe four) drops of hot water into the ink port in the printer and two drops into the ink port on the cartridge then snap the cartridge back in position.  

It may also help to manually clean the printhead as described in the post here.

I have also seen cases where leaving the printer overnight after the cleaning cycles allows black to recover.

If none of the above restores black printing your printer will likely require repair or replacement.