Dell 3115cn Color Laser Printer User Manual page 92

Before turning on the multifunction printer, be sure to release the carriage lock of the scanner.
NOTE: If you use the optional duplexer, remove the protection film attached to the transfer belt unit
of the duplexer. For details, see
NOTE: When you are moving the multifunction printer or do not intend to use it for a long period of
time, move the switch to the lock position.
1. Plug one end of the printer power cable into the socket at the back of the multifunction printer and the
other end into a properly grounded outlet.
CAUTION: Do not use extension cords or power strips.
CAUTION: The multifunction printer should not be plugged into a UPS system.
2. Turn on the computer and the multifunction printer.
"Installing a Duplexer".