Banding Issue imagePROGRAF PRO-4100

[MelissaC]

I have an imagePROGRAF PRO-4100. I'm trying to print photos on 17x22 silver rag paper, which I have successfully done in the past, but right now I'm having banding issues which are only affecting the large size. 

I've tried on 8.5x11 of the same type of paper- no problem.

I used a 13x19 glossy photo paper- no problem. 

I was on the phone with Canon for an hour yesterday emailing photos of nozzle checks and doing cleanings. I've done a printhead adjustment, the inks are actually new. We thought maybe it was the CO, but I printed with the clear coat turned off and it still did it. If it wasn't printing correctly on other papers, I would think it was a printhead issue. What on earth is happening? 

[MelissaC]

Update: I switched to the roll paper, and the banding stopped. So it's a feeding issue. While we were troubleshooting, I did do two feed adjustments. 

Is there a way to clean the interior feed rollers? Because it was printing on sheets before and now it's not, so something physical in the machine is different. I've cleaned the feed rollers on my Pro-100 before. Has anyone done that for a bigger printer?