Thanks for your response:
Even if the valve or damper parts were available, I don't have the tech skill to replace them. I will stay on matte black.
I'm not clear on your second point. If I switch back to PK, then the deluge of ink will mess things up again. How would the PK empty out if it's...
I haven't used the photo black in some time, so I decided to make that switch from matte to photo black.
This resulted in a big black ink mark mess on one test paper after another with the nozzle check showing many gaps on each channel.
I switched back to matte black, but still have ink marks...
The printer has less than 500 prints, so I presume there's still much life left in this machine.
I wanted to do some preemptive maintenance.
The other day, using Windex (no ammonia), I cleaned the purge pads and wiper. Lots of black ink came off on those Q-tips.
Nozzle check pattern shows...