We have a brand new 5130cdn Color Laser. It's printing black blotches all over most pages, anywhere from pinpoints to the size of a pencil eraser, several dozen per page, no discernable pattern.
The first thing I would check is to see if the printer or driver is causing the issue.
You may test the unit by printing a settings page from the unit - from the printer: menu - report / list - printer settings.
This will print a settings page from the printer and will allow to know what the next possible step may be.