Canon imageCLASS MF4690 Operation Manual page 243

Message
SYSTEM ERROR
TONER COVER OPEN
CLOSE COVER
TONER LOW
PREPARE NEW TONER
UNKNOWN USB DEVICE
USB MEMORY FULL
11-20
Description
Some kind of error has
occurred in the machine.
A cover is open.
The toner is running low.
A USB device which is not
supported (e.g., USB mouse,
USB keyboard) is connected to
the USB memory.
The USB memory is full of data
or the number of file limit has
reached.
Action
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 Canon Customer
Care Center.
Check the cover, and make sure
that it is completely closed.
Prepare a new toner cartridge.
Do not connect anything other
than a USB memory.
Get enough space in the USB
memory or organize your
destination folder from your
computer.