Panasonic FP-7750 Black Copier

Sounds like fuser issue ( The Fuser Heats the Toner and Fuses the toner to the paper) It could also need a developer change depening on the amout of copies you have on the machine. Unless you can rebuild the fuser or replace the developer, you will have to call a service tech. If your in Maryland you can contact Innovative Copy Products if not go to panasonic.com to find a local dealer