
Troubleshooting
11-20
Message
Description
Action
SYSTEM ERROR
Some kind of error has
occurred in the machine.
Turn off the main power switch,
wait for more than 10 seconds,
then turn it on again. If the
message persists, turn off the
main power switch, disconnect
the power cord, and contact
your local authorized Canon
dealer or the Canon help line.
TONER COVER OPEN
CLOSE COVER
A cover is open.
Check the cover, and make sure
that it is completely closed.
TONER LOW
PREPARE NEW TONER
The toner is running low.
Prepare a new toner cartridge.
UNKNOWN USB DEVICE*
A USB device which is not
supported (e.g., USB mouse,
USB keyboard) is connected to
the USB memory.
Do not connect anything other
than a USB memory.
USB MEMORY FULL*
The USB memory is full of data
or the number of file limit has
reached.
Get enough space in the USB
memory or organize your
destination folder from your
computer.
* MF4690PL Only