Lexmark CX725
Remove the imaging unit.
Remove the controller board shield. See Controller board shield removal.
Disconnect the toner cartridge contacts cable (A) from the controller board.
Remove the screw (B), and then push the tab (C) to the right.
Push the cartridge contacts assembly into the printer.
Remove the cable from the retainer clips, and then remove the cartridge contacts.
Remove and insert a new toner cartridge when you continue to see faded prints.
Update your database of contacts by adding the information in the Address Book.