My 4100S seems to have a banding issue with cyan. This printer is new and only 3 weeks old.
In this first picture you can see the left side is printing correctly but as the print advances banding begins to appear and the color is faded. My guess is a problem with cyan and the printhead not getting enough ink.
(Note there are splotches in the swirls as part of the design.)
In the top print you can see how the colors appear faded and are grainy when looking up close. I noticed the red sections and yellow sections printed perfect. Blue is the most affected, followed by purple, and green. For this reason, I believe the problem to be specifically with cyan.
I ran a cleaning cycle on all colors and after printing a nozzle check I noticed the cyan grid was still missing a horizontal line. After running another cleaning cycle on pattern 1 the nozzle check printed perfectly.
I ran another print which is displayed below the initial print. You can see it printed darker but still had slight banding.
Right pictured print was the initial, left was after the two cleaning cycles.
Another image comparing the two prints:
First nozzle check after one cleaning cycle on all nozzles.
Second nozzle check after P1 nozzle cleaning:
I then printed a third to verify this was solved. The print that came out looked like the initial faded print. I ran a deep cleaning cycle on all nozzles and began printing a fourth. This fourth print began printing faded, then there were a few spall horizontal passes that printed dark as it should, but then it returned to faded for the rest of the print and I canceled it.
I believe I narrowed this down to a problem with the cyan. Are the nozzles not getting enough ink?
If the cyan nozzles are being starved for ink could it be the ink hose is not making a good seal with the print head?
Welcome to the forum.
"My 4100S seems to have a banding issue with cyan. This printer is new and only 3 weeks old."
I wouldn't be checking here. Call Canon and get service. They should go over the whole setup and ensure everything is correct.