Won't print black ink in large format

[Omar-E]

http://h30434.www3.hp.com/t5/Inkjet-Printing/Won-t-print-black-ink-in-large-format/m-p/5468805/highl...

alyc317

Product Name: Officejet 7612

Operating System: Mac OS X 10.11 El Capitan

This printer just refuses to print in a deep black when printing large format (11x17).  If I'm in Word and print on quick print setting, black & white, it will print in black (letter size).  But if I print from photoshop - select greyscale, black ink only in printer settings, no matter what I do, it refuses to use the black ink AT ALL.  The CMY inks drain while the black stays FULL.  It hasn't been touched.  The result is a muddy green-grey instead of a deep black and a picture that looks absolutely terrible. I've read about other printers here not using black on large format and I'm baffled if that's seriously the case.  Who would want a large document to turn out so muddied because the printer refuses to use the black??!

[Omar-E]

This printer just refuses to print in a deep black when printing large format (11x17).  If I'm in Word and print on quick print setting, black & white, it will print in black (letter size).  But if I print from photoshop - select greyscale, black ink only in printer settings, no matter what I do, it refuses to use the black ink AT ALL.  The CMY inks drain while the black stays FULL.  It hasn't been touched.  The result is a muddy green-grey instead of a deep black and a picture that looks absolutely terrible. I've read about other printers here not using black on large format and I'm baffled if that's seriously the case.  Who would want a large document to turn out so muddied because the printer refuses to use the black??!

[Sunshyn2005]

@DocCottle