I have taken out the toner and shaken it, but yellow still not printing, and color images look awful. Any help greatly appreciated.
Thanks, but it didn't work I think the printer has a hardware problem. Printing out the Pantone color chart, and all yellow boxes are still not showing up on paper.
And oddly that is exactly what Niveks post typically solves.
I pulled out the imaging Unit and cleaned it and there was no yellow toner on it, but there was lots of cyan, black and magenta. I'll try the menu fix again now that I finished cleaning it and turned it back on.
Again, follow the link in Niveks post, it fully explains step by step how to go into diagnostics and run the toner motor to move the toner into position.
Nope, since you have done into diagnostics and forced it to empty toner directly into the machine and still have nothing coming out the issue has no relation to the toner, has to be a drum problem, not the toner.
You will need to either replace more stuff or get a service tech to figure it out