Hi James1126,
Thank you for using the Support Forum. Please try switching to the Run Black feature and see if black prints properly in that mode. If the prints are still light try a new black toner cartridge. If it prints fine with the run black mode please power off and back on. If the problem continues please consider contacting your support centre for further assistance.
All the other colors print as dark as they should. Black comes out about half as dark as it should be. We've tried new toner. We've also tried the various maintainance options in the menu. Do you have any idea what could be causing this?