PIXMA TR8620 printing issues - black text prints intermittently

[MLG]

I upgraded to MAC 12.7.6 and printing with the TR8620 was fine for a couple of months - until it wasn't!  Black printing is intermittent or prints partial words; color is fine.  Nozzle check is perfect, but I did a couple of cleans and a deep clean.  Print head alignment completed.  I reinstalled software including a new driver, updated firmware. Printer Test Page shows a few words, rest is "streaky"/incomplete with the color portion fine. Canon print cartridges used. I am able to print some saved pdfs but not others.  Has anyone else seen this?

[DerrickL]

How is the ink level in the black cartridge?

[MLG]

Levels were good throughout the testing.   I replaced the small one (BK 281) just to see if there would be a change, but no difference.  PGBK (large one) is about 1/3 full.

[jrhoffman75]

Give Canon support a call at 1-800-OK-CANON

[DerrickL]

I found this forum thread posted by a user with what seems like the same issue you are having:

https://www.printerknowledge.com/threads/no-pigment-ink-printing-from-tr8620.16187/

[MLG]

Thanks for the advice.  I tried printing again with no luck (several different pdf's, a spreadsheet page, etc.), but decided to see if I could copy in black.  That worked.  Then I went back to printing a pdf and that worked too.  Is it possible copying reset some sort of setting?  Same type of paper too.

[MLG]

Thanks for checking on this.  Not quite the same.  I got some black printing and my nozzle check page was perfect, unlike the person in the thread.  I decided to try copying a page in B&W and it worked.....I went back to trying to print and now I am able to print in black too - pdf's and other types of documents.  No idea what changed.