Make sure there is paper in the printer. Also, make sure there are no jams by opening the top of the printer and the rear door checking the paper path.
It's most likely time to replace the toner cartridge.
Contact your dean and have him/her contact Marge Trollinger in the graphics department for toner cartridges.
Refurbished cartridges do not have the same quality control OEM cartridges have. Simply take it to Marge in graphics and she will replace it.