OfficeJet Pro 6960 - Issues with black ink - smeared/not printing

[MCregan]

I've had an OfficeJet Pro 6960 for the past 2 months and recently it's started having printing issues; black ink specifically.

At random, documents will print with a white smear/fading through any section of black ink, or simply not use any black ink whatsoever. Cleaning the print head will sometimes rectify it and other times have no effect. A correct test page should look like the one below:

But some of the results I'm getting look like this: 

Or even like this:

I've taken the cartridge out and reseated it, made sure there were no vent blockages and that the printer itself was unobstructed. The cartridge is a genuine HP XL one, it was only changed a little over a month ago and going by the printer itself, is still over 50% full, so I don't think changing it is the answer.

Especially given that at random it will start printing fine again without any smudges or smears. But just as soon as it goes back to normal, it starts acting up again and can take up to 5 attempts at printhead cleaning to start working again.

My major issue is that I'm signed up to HP Instant Ink, so I'm losing pages from my monthly allocation for every one that comes out half right. Not to mention the fact that I'm losing ink out of each of the colour cartridges with every test page. Is there another solution available?

[sabretooth04]

Try here.

https://support.hp.com/us-en/product/hp-officejet-pro-6960-all-in-one-printer-series/8289579/documen...

Let us know.

[MCregan]

Hi, thanks for the reply. I've done all the steps in the above link:

1. Genuine HP cartridges - using the ones I get through HP Instant Ink
2. Smears on back of printouts - no smears on the back
3. Correct paper - Standard white A4 paper, same type I've always used
4. Print settings - All as standard in both Windows & Mac (using both & phones as this is a network printer)
5. Estimated ink levels - Black above 50%, some of the colours are a bit lower, but as it's only black that's giving issues in printing I don't think that has anything to do with it
6. Replace low/empty cartridges - All were replaced a few weeks back with the Instant Ink cartridges
7. Cartridges correctly seated - All in their correct slots, no blockages, reseated just in case
8. Print Quality Report - When the black is printing without issues, everything seems in order: 
9. Test pattern 1 - Lines were straight and connected
10. Aligning print head - When the black was not printing, this had no effect in rectifying it
11. Reprint pattern - Still the same
12. Test pattern 2 - Colours were solid

13-18 Clean the printhead - This seems to be the only thing that has any effect. When the black ink starts to miss sections or stops appearing altogether, it usually takes between 1-3 printhead cleanings and it will go back to normal, but only for a while.

After the last cleaning, it took around 20 documents or so for it to start acting up again. Again, another printhead cleaning rectified it and I haven't seen any problems since, but it's probably just a matter of time.

I can understand an older printer requiring more frequent cleaning, but for one that's only 2 months old it shouldn't be necessary surely.