First thing is to print the blank pages
2nd thing is to do the troubleshooting pages
3rd thing is to clean the yellow LED
4th thing is to replace the yellow drum/imaging unit
The assumption would be that it is a drum/imaging unit assuming the page is being fed left-right, but if it is fed from top-bottom I would think it was toner spilled on a roller.
No more than assumptions since you did not specify the printer in question.
It couldn't hurt to run 5-10 blank sheets through whatever printer it is just to clean up the rollers though.
Everytime I print something a horizontal yellow band abouth 5/8ths of a inch prints at the top of the page. It appears to be a bunch of yellows lines rather than a solid band. Does anyone knwo how to get rid of this or how I can fix it?