My CP5525dn color laser printer has a banding issue that i have yet to solve. About half way down the page is a vertical line of lighter color. We have had the transfer belt replaced (not related) and have gone through multiple color and black toners and nothing seems to fix the issue. Because it's very faint it's not worth getting someone out to fix it...yet. But if anyone has tips that could help diagnose the problem i would like to try and fix it.
Possibly helpful is that the transfer belt was replaced due to scratching that occured after we printed about 10k pages of pre hole punched paper for a project. This clogged up the excess toner collector at the top of the toner run. Now we didn't replace the toner pick up so maybe it's still clogged up. Any suggestions are appreciated.