Canon MX520 series Online Manual page 179

5100
Cause
Printer error has occurred.
Action
Cancel printing, turn off the machine. Then clear the jammed paper or protective material that is preventing
the FINE Cartridge Holder from moving, and turn on the machine again.
Important
Be careful not to touch the components inside the machine. The machine may not print out properly if
you touch it.
If the problem is not resolved, contact the service center.