HP PageWide Color 556 - Right side of the page not printing in Black (other 3 colors print fine)

[DashMartin]

About 2 inches are not printing on the page on the right side in black. It doesn't appear as if the print head is easy to inspect. Ran the cleaning cycle multiple times. No change. Issue appears whether printing from a PC or a test page directly from the printer. Haven't been able to find this issue reported or a resolution (besides running the cleaning). Running out of ideas. Was purchased in 2017.

[DashMartin]

Bump

[E_P_E]

Hi, There was a printhead recovery procedure in the service menu of the Pro X models that was sometimes effective at recovering lost segments or that I use to call the waterfall effect (like the printhead starving of ink). 

Hit the lower right return on the LCD 4 times in sequence as I believe this still provide access to the service menu and they look thru the menu for anything that sounds like a "recover" process or something called a "tap test." Some say one of the tap tests replaced the printhead recovery process. 

I'm also working on a tool that I believe may be able to recover this issue assuming it's not an electrically dead printhead segment. 

To access the printhead just open the left hand side of the printer and remove the duplex / waste ink tray at bottom (you should really clean this out every 10,000 pages or so anyway and be sure to get hot water under the front covered area as that is where the spit roller wiper blade is), then drop the latch just above where this tray was. The printhead will drop down such that you can wipe it clean (always use a very damp pad of folded paper towel or lint free cloth...the wetter the better if there is anything possibly on surface or clogging the nozzles) and even see it with a small dental mirror about 1 inch back and 1 inch up.

I'll be posting a Pro X and Pagewide Printhead recovery instruction on HP's forum soon if my tool works as I believe it will. I worked at HP for 8 years and I really wish they were more intent on helping the customers that bought these printers. The are very good printer but are simple too sensitive to air/gas collecting inside the ink delivery system.