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New Contributor
Posts: 1
Registered: ‎08-11-2019

Re: printer not printing black

I did a search of most all the posts and answers and didn’t find and answer to my PGBLK problem of not printing...

Model: PIXMA, MG7500 series
Problem: When using Plain Paper among with Photo Printing on the setup, PHBLK will not print. All other colors work ok. BUT, PGBLK works when I use photo paper instead of plain paper. What’s up with that? How do I get it to print blacks on plain paper?

Setup is up to date Windows 10. Thanks.
Product Expert
Posts: 875
Registered: ‎11-19-2018

Re: printer not printing black

Hi Jv1e,


Please contact our support group at 1-800-OK-CANON (1-800-652-2666), Monday - Friday, 8:00 AM - 8:00 PM EST.


We look forward to hearing from you.

New Contributor
Posts: 1
Registered: ‎08-20-2019

Re: printer not printing black

I have a bit of good news. The black (large) ink cartridge is nororious for clogging and I think I understand why. And I fixed it myself.


When you print a lot of 2-sided documents, the printer switches to the pigment (small) black cartridge to avoid smudging when the paper if flipped. As a result, you'll wear out that ink tank much faster! You'll also under-utilize the large black ink tank (PGBK). I also leave my printer on all the time, even when I'm travelling away for weeks. Maybe these two things combine to cause the case where the PGBK ink just dries up.


To avoid this... set simplex printing for text at least once per week. Or do a print head cleaning (selecting only the PGBK tank) for the cleaning once every two weeks.


So, you're not printing from PGBK at all (based on doing the Nozzle Check and not seeing ANYTHING at the top row where you should see something for PGBK). This means the ink is most likely really badly clogged.


For everything below, do at your own risk. You may have a different issue than I had, but from what I see from this thread, there are no solutions offered to this very common problem. But you could potentially damage the print head. In my case, I was considering buying a new printer if this didn't work, so it was my last resort.  Read on.


There are cleaning agents out there for your print head that don't require removal, but for me, this worked best:

Create some cleaning solution: (1 cup filtered water, 3 drops dish washing detergent, 3 teaspoons Isopropyl alcohol) -- heat the water first in the microwave not to boiling but hot to the touch, then add the soap and alcohol. This is exactly what is in those "professional" cleaning solutions. The only tool you'll need is a plastic syringe. Those are cheap.


Remove the print head by following the various you-tube demos for the MX-922. It's easy, and much safer in my opinion than messing with a tight workspace. When you get the print head out, don't touch the print heads where the ink jets are. If your print head is an utter mess of ink and dirt, it's safe to run it under hot tap water. If you get the electrical contacts wet, don't worry too much. I'll discuss more in a sec about that.


Use paper towels in a sink as your work surface, and put the print head ink-jet-side down (the paper towel will start to soak up some residual ink, but that's okay). You want to unclog the larger black ink cartridge port, so I'll focus on that one. I used a cheap plastic syringe, but I cut out the center "nipple" so that it has a contact "ring" that matches the size of the PGBK ink input screen. Suck up 5 - 10 ml of your hot cleaning solution in the syringe, gently place it over the PGBK ink port and start injecting the fluid. It will be messy and not all go in, but some will. The act of pushing the hot fluid in there will loosen up the gunk, but be patient. It takes a LOT of 5 ml syringes-full of fluid, and you want to use at least half of the cup of cleaner you made in this process. You don't "pull" on the syringe, but PUSH fluid in, and avoid air bubbles as that may damage the print head. Now, if the clog is on the ink jet side (or if it's so gummed up you can just tell), I recommend very lightly using a q-tip, dipped in your cleaning solution, to clean up the ink jets, but don't apply any pressure. If you're nervous, just run hot tap water over the ink-jets instead.


When you know the clog is cleared is when you dab a "dot" of cleaning solution on the input port and a few seconds later you see it absorbed. If it's still staying as a "bead" of liquid, it's still clogged and you need to keep going. Some recommend walking away for 20 minutes or so (to let the cleaner do it's work internally), then come back and push more in with the syringe for a final cleaning. I didn't do that.


Blot as much of the moisture as possible, and if you have one, use a can of computer spray duster (compressed air) to speed up the air drying of the electrical contact part of the print head, and nearby parts that you can't get to by blotting with a paper towel.


Also, bonus points if you take a 2nd syringe with a blunt needle on it, suck up some black ink from an old cartridge (or spare ink tank if you have refills), about 3 - 5 ml, and gently "bead" it on top of the PGBK port until it absorbs, and there's an ink mess coming out of the ink jets as seen on your paper towel blotter. That means you freed up the clog, or at least some of the clog!


If you do the re-inking, it can be messy, so blot up any spillage, dry everything reasonably well, and re-assemble the print head into the printer (following trusty YouTube videos).


Run a "Cleaning" operation once, then do the Nozzle Check. If everything looks perfect, you're done! If there are some streaks still in the PGBK section, you might have to run a few more Cleaning (just for that one, not the color cartridges), and try the nozzle check again. In my case, after I did the 3 - 5 ml of ink recharge before re-assembling, I got a perfect nozzle check pattern.


Then probably do a print head alignment routine.


Good luch & peace out

Occasional Contributor
Posts: 7
Registered: ‎10-01-2017

Re: printer not printing black

Hi Christacen,

You really make this sound like this will work! I hope so! I will try your solution soon and report on my success here. In the meantime I bought another printer, a HP 3830, that I've had no problems printing at all for the past 1 1/2 years.



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