lovingtruth
Print Lurker
- Joined
- May 24, 2026
- Messages
- 3
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- Printer Model
- HP OfficeJet Pro 6978
I really hope that this forum can help me with this problem. I've been working on it for over 3 weeks and feel that I have exhausted what I can find in internet searches.
Basically: I have a used OfficeJet 6978. It worked perfectly for about 100 pages until the black ink started coming out faded, then stopped, over a number of pages of a big job. I stopped the job and have been at it ever since.
First, I ordered ink refills and filled the cartridges. They all worked after this except for black. I realized that the printhead may be clogged. I found this video
and performed the flushing with isopropyl about 5 times until it ran clear, then later learned that ammonia/isopropyl 90/10 is a better mix, so did that as well. The flush ran clear. It didn't work.
Then, I found this thread https://www.printerknowledge.com/th...e-heads-in-the-cleaning-solution.15643/page-2 that suggested soaking the head. I soaked it in the 90/10 mixture. A lot came out in the water! But, I wonder if that was from residue on the plastic, and not anything actually stuck in the screen/filter/white circle thingy.
Putting the head back in and running print tests, including the printer's cleaning function, resulted in zero change. Stark white where black should be.
At some point during this process, somewhere in the middle, I did get some very light and patchy black text, but that was only on a couple of sheets, and it disappeared again.
I did completely fill the black cartridge, btw. I didn't count how many syringes it took, but it was a good number, maybe 8, and I had to stop when it stopped going in.
Please, any suggestions?
Basically: I have a used OfficeJet 6978. It worked perfectly for about 100 pages until the black ink started coming out faded, then stopped, over a number of pages of a big job. I stopped the job and have been at it ever since.
First, I ordered ink refills and filled the cartridges. They all worked after this except for black. I realized that the printhead may be clogged. I found this video
Then, I found this thread https://www.printerknowledge.com/th...e-heads-in-the-cleaning-solution.15643/page-2 that suggested soaking the head. I soaked it in the 90/10 mixture. A lot came out in the water! But, I wonder if that was from residue on the plastic, and not anything actually stuck in the screen/filter/white circle thingy.
Putting the head back in and running print tests, including the printer's cleaning function, resulted in zero change. Stark white where black should be.
At some point during this process, somewhere in the middle, I did get some very light and patchy black text, but that was only on a couple of sheets, and it disappeared again.
I did completely fill the black cartridge, btw. I didn't count how many syringes it took, but it was a good number, maybe 8, and I had to stop when it stopped going in.
Please, any suggestions?
