Its either a bad toner cartridge or a bad fuser. Perform a 1/2 page test to confirm which part has the defect and swap it out accordingly.
Halfway/Half page test:
http://www.printertechs.com/printer-troubleshooting/halfway-test
Its either a bad toner cartridge or a bad fuser. Perform a 1/2 page test to confirm which part has the defect and swap it out accordingly.
Halfway/Half page test:
http://www.printertechs.com/printer-troubleshooting/halfway-test