Dell 3100

I use the Dell 3100cn laser printer in my classroom. However, recently the print quality is horrible in documents with color. There's always a thick line on the right side, and then half way down the page it always looks like it smudged, then corrects itself. Nothing I print out in color is presentable.

My inkjet printer has software to clean the printheads, which helps print quality if needed, I thought pehaps there was something similar for a laser printer?

Thanks.