When a Problem Cannot Be Solved

If you cannot solve a problem by referring to the information in this chapter, contact your dealer or service representative or the Canon help line.


Do not disassemble or repair the machine yourself If you disassemble or repair the machine yourself, it may not be covered by warranty.

When contacting us, have the following information ready:

Product name (MF842Cdw)

Dealer where you purchased the machine

Details about your problem (such as what you did, what happened as a result, and displayed messages)

Serial number (found on the label on the back side of the machine)


Checking the serial number from the control panel You can also check the serial number by pressing the [Counter/Device Information] key.