Dell S5830dn Faded Print Jobs

We use a number of Dell S5830dn here on campus (unfortunately they are out of warranty) and we are experiencing faded streaks in prints. All printer levels appear to be good. However, there are light streaks at different spots on various printers. Some are faded on the edges while others are faded in midsections. Can anyone advise on how to trouble shoot this issue? Some googling has not yielded anything specific to that printer model and there seems to be quite a bit of variation from model to model. See attached images for details on printer configuration and a faded print. Any help would be greatly appreciated.

Best.Faded printPrinter LevelsPrint qulity settings