DIAGNOSIS The main system controller has locked up, usually due to a firmware glitch or a brief power surge during operation.
FIX Perform a hard reset by disconnecting all cables.
- Turn the printer OFF.
- Unplug the power cord AND the Ethernet/USB cable from the back.
- Wait 3 full minutes.
- Plug ONLY the power cord back in and turn the printer on. The screen should go through its full boot sequence.
IF THAT DIDN'T WORK You may need to force a firmware recovery. Download the latest firmware .rfw file from Canon's support site for the MF453dw onto a USB drive. With the printer off, insert the USB, hold down the Stop button, and press Power. Keep holding Stop until "Update" appears, then release.
HEADS UP Avoid using the printer on a power strip with other high-draw devices like space heaters. Use a surge protector to prevent voltage spikes that can cause these lockups.