Epson ActionScanner ActionScanner II Getting Started page 6

3. Locate the round screw in the middle of the rear panel and
turn it counterclockwise. If necessary, use a coin to loosen it.
4. Remove the screw and push it into the storage hole marked
STOCK;
do not screw it in.
5. Connect one end of the power cable to the power inlet on
the rear of the scanner and plug the other end into an
appropriately grounded electrical outlet as shown below.