PGBK not printing at all – missing from nozzle check (PIXMA iP8720)

[Kavery7200]

I’m having an issue with my #CanonPIXMAiP8720 and hoping for some guidance

I recently replaced all ink cartridges with genuine Canon cartridges (PGI-250 / CLI-251 series). After installation, I ran a nozzle check.

• Cyan, magenta, yellow, black (BK), and gray all appear and look normal
• However, #PGBK (pigment black) is completely missing
• It does not print at all and does not even show on the left side pattern indicators

I have already:

• Performed standard cleaning cycles
• Previously ran a couple of cleanings before realizing some cartridges were empty

At this point, the nozzle check looks normal for all colors except PGBK, which is entirely absent.

My questions:

1. If the PGBK nozzle is clogged, is it normal for it to be completely missing from the nozzle check (no pattern at all)?
2. Could running cleanings while some cartridges were empty have caused this?
3. What would you recommend as the next step:
   
• Additional cleaning/deep cleaning?
• Manual printhead cleaning?
• Or does this indicate possible printhead failure?

below is my most recent nozzle/pattern check

 

[jrhoffman75]

Cyan and magenta test patterns are not correct.

You might want to contact Canon support at 1-800-OK-CANON and discuss with them.

[DerrickL]

If you know that all the ink cartridges have ink, try doing a deep clean again, then another nozzle check print.