HP C7280 not printing black

[PaulAm]

Anyone here ever fix one of the HP C7280 inkjet multifunction printers?

I have one that stopped printing black.  Even with a new HP cartridge nothing black prints.  The printer thinks it's printing, but there's nothing on the paper.  Doing the print head cleaning cycle (multiple times) doesn't change anything.

Doing a google search on this yields a couple million hits but no effective technical advice.  The summary would be a) return to HP for service or b) buy a different printer.  I'd rather fix the one I have rather than adding to the landfill problem.  Anyone got any pointers?

[m3vuv]

had the same issue with a cannon once,ended up using a shringe with some plastic tubing to shrynge hot water into the small nipple where the ink tank passed ink into the print head,did it about 6 or 7 times untill clear water came out of the ink nozzles ,dried it out refited the ink cartrige and it was fine.

[tooki]

If I recall correctly, this is one of the HP models that uses dual vacuum pumps for nozzle maintenance (one that sucks from the nozzle side, like most inkjets have, but also a second one to suck from the back, to back out clogs rather than try and force them through the nozzle). Most likely, the pumps are also used to prime the whole system. If there’s a leak or a pump has failed, then the ink isn’t going to make it out of the cartridge.