I have an older HP 4 in 1 printer/scan/fax--Officejet 6600. For some reason, I bought a different printer and was using the newer one for a year or so. Recently returned to using the 6600 and it was working, until the black ink cartridge emptied. Bought a couple of new black cartridges..correct number..and put one in. Printer works fine......printing with the color cartridges, but the NEW black cartridge didn't print. Tried the other NEW black cartridge. Still no black ink being applied to paper. Printer THINKS it's printing. No help screens, or advisory screens. Printer does its thing, and spits out a nice printed sheet, but uses ONLY the color cartridges......so, in reality, there's not much printing on the completed sheet.
Computer shows new full black cartridge.... Printer is just not accessing the black ink cartridge. Do the "connections" ever plug up with dried ink, or something else? What would prevent the ink from passing through the system? Is there a way to clean out the passageways? Any thoughts? thanks. showboat