I have purchased Canon printers for over 30 years, but I think I'm switching to Epson or some other brand now. Two years ago I bought a new Gold Color Canon Pixma MG7720 printer. If you checked Walmart, Amazon, Ebay, you can only find them new in black color now days, and they will cost $600 to $1,000 as of Sept. 2021. And there is plenty for sale as "parts only".
Anyway, it only gets used 2-3 times a week since I bought it, and not usually over 25 sheets a week, and occasionally a photo or two. Last month I started having trouble with the PGBK printing bad. On running a test it was printing a bad grid pattern. So, did some research and did about every thing people said to try to do. Ran the deep clean, cleaned the printer head, ran the alignment program several times, and the manual alignment too. Replaced that PGBK ink tank twice. Cleaned off the printer timing encoder.
Bought a printer timing encoder and a new print head, and guess what, like the rest of you, it still does the same thing. So, I phoned Canon Support and they more or less told me to throw it away, I could have a discount on a new printer, and guess what, none of the new Canon printers will use the approximately $200 of new ink cartridges in my drawer either! And support also informed me that I could not get a repair manual for it either! I'm a farm girl taught by daddy not to fix it if it ain't broke. But when it is broke, try to fix it. I build my own computers, and will dig into fixing if I have a good repair manual.
My last Canon printer was a Pixma that almost lasted me 10 years. But I see the people who's MG7720 and numberous other related model Canon printers using PGBK ink with a printer timing encoder, have the same trouble with the PGBK bad grid print, and it usually happens after the warranty is off or by 2 yrs of age. So, I'm inclined to wonder like many, that Canon has them programmed to cause this problem, just to sell more printers! Or that maybe the reader of the printer timing encoder is either dirty or went out, and Canon will not provide any info on that matter either. I'm VERY DISAPPOINTED with Canon now. Since I have to try to sell my ink, I will go with another brand printer too! Canon, you are cheating your costumers on this massive problem with the rabid PGBK problem of the bad grid print! IT'S NOT APPRECIATED BY YOUR COSTUMERS!