My MF743Cdw has recently started printing double sided jobs incredibly slowly. It doesn’t matter if I have a two page job or a 40 page job, or what device it is printed from. Even copy jobs are slow, so it’s not a driver issue. Firmware is updated, printer has good ventilation.
This is only an issue when printing double sided. Single sided prints still go nice and quick.
If the duplex is slowing down for prints and copies, you can try reseating the toner in the printer and checking for any obstructions. If that does not resolve the issue, it looks like there is something wrong with the paper feed. I would suggest contacting our support team at 1-800-652-2666. Our agents would be happy to check on the issue for you and to provide any service options.