SamsungDCS-408 & 408i Keyphone System Installation Manual– 12 –1. Drill three holes in the wall at the positions indicated for the screws using an electric drill.CAUTION: If the wall is made of plaster or brick, or if the building is prefabricated, you should fixa wooden board having a thickness of about 2 cm to the wall and drill the holes in this.Otherwise, you may damage the wall.2. Insert the screws into the holes you drilled. If the wall is made of concrete, you will firstneed to insert the rawl plugs into the holes and then insert the screws into the plugs. Fas-ten the screws, leaving each one protruding sufficiently to be able to support the system.CAUTION: If you insert screws directly into concrete walls without using rawl plugs, the systemmay not be fitted securely to the wall.3. Fix the unit securely by locating the protruding screws in the grooves. Testing Initial System OperationCheck that the system operates normally before you begin connecting any cables to the unit.1. Make sure the AC power switch is off.2. Connect the power cable to the AC INPUT connector on the unit and to an AC mainspower socket.3. Turn on the AC power switch. Check that the red LED inside the cover on the lower right-hand side is flashing..Rawl plugScrewHole