I recently purchased a MF634CDW direct from Canon for my home office. I set it up and seemed like all was OK, but my wife reported that the machine had an error message. I power cycled and then it seemed fine, but I now realize that whenever the device goes into sleep mode, and you send a print job, it displays an error message and you have to power cycle to get it to function again.
I am not using the wireless functionality and am using the wired network. Other then turning off the sleep mode altogether and accepting that this device has flaws, I don't have another option. I downloaded and installed the latest firmware but it did not fix the issue.
