An OfficeJet 7500A Wide Format MF not printing black with new cartridge NOT a hardware problem.

[dpluna]

Although there was no out-of-ink or error message, my little-used OfficeJet 7500A Wide Format MF stopped printing black at all for some reason.  Thinking that replacing the cartridge with a new one might fix the problem, I did but it didn't.  So, I used HPs Print and Scan Doctor to clean the print heads and aligned the heads.  No luck after doing that twice. 

Disconnecting and reconnecting the USB and power cables, as also suggested, had no effect either.  I'm not big on Chat and eventually, was able to reach an HP tech on the phone.  He had me do again the same things I had tried and when those failed again, he concluded I had a hardware problem that wasn't practical to try to fix and offered to upgrade me to a much later, reconditioned high-end Multi-function ink-jet for about half price and I went for that, with it to arrive tomorrow.

Today I got an email from HP Support offering an update of the Print and Scan Doctor and just for the hell of it, used that to clean the print heads again.  And, guess what?: black printing suddenly was functional again and crisp!  Yellow was looking somewhat streaky but running the print head cleaning one more time, cleared that up. 

So the message here is don't stop at one or two attempts at print head cleaning if there's any reason to think a further attempt or two possibly could finally fix the problem.  Whatever the downside of doing that too many times, it's a lot less than having to buy a whole new machine, as I did.

[Bob_Headrick · Accepted solution]

The black not printing issue may be caused by a clogged printhead.  In some cases printing may recover if the printer sits.  The troubleshooting steps in the document here may help if you have issues in the future with black not printing on this printer.

[dpluna]

That certainly appears to be what happened and the suspicion that that might be the problem probably was what prompted me to try for maybe the fifth time by then to clean the printheads yet again after several days of the machine just sitting there.

Had the HP tech I talked with in the meantime suggested that, I would have tried it before accepting his conclusion that it was a "hardware problem" and his intimation if not saying outright that there was no practical thing to do but replace the printer.  Whereupon he offered to replace it with an HP-reconditioned OJ Pro 8630 at a price which seemed to make it probably my best option. 

Since the 8630 had already arrived when I again retried cleaning the printheads on the 7500A and the 8630 had several desirable features the 7500A didn't, I decided to keep it; since have set it up; and am happy with it.  But I would have been just about as happy sticking with my 7500A and not going to the considerable expense and bother it was - as it turned out - to needlessly replace it.

As for the troubleshooting steps you linked, I certainly wish I had found them in searching for help on HP's Support site but, for whatever reason, I didn't until now.  Not only did I "favorite" them for any future incident with the 7500A - if I ever use that again - I'll refer to it to find a path to similar steps for my 8630 and Designjet T520.

Thanks very much for your help on this.  Hopefully, others encountering the problem I did will profit from it.