I am experiencing very dirty printing when using the paper tray feed - I have cleaned the rollers as directed in other internet posts.  This only started within the last couple of weeks.

IF I pirnt one page at a time using the manual feed. the output is fine. 

I have a new toner cartridge so that is not the problem.

 

Any ideas - I cannot determine why the tray feed is making a dark page come out and the manual one-page-at-time is just dandy.