Abstract: A method for identifying video signal source is provided. The method includes the following steps. A first identification code is assigned to a first transmitter device by a receiver control unit of a receiver device. A first video data is transmitted by the first transmitter device. The first video data and a first identification image corresponding to the first identification code are combined as a first combined video data by the receiver control unit. The first combined video data is outputted to a display device by the receiver control unit.

Abstract: A board member mounting structure includes a first board member having a number of recessed portions and an opening in each recessed portion, a second board member attached to the first board member at right angles and having locating notches corresponding to the openings in the recessed portions of the first board member, first fastening members each having a flat head fitted into one recessed portion of the first board member and a shoulder extended from the flat head and fitted into the opening in one recessed portion of the first board member and a bolt downwardly extending from the shoulder to the outside of the first board member, second fastening members respectively mounting in the locating notches of the second board member, each second fastening member having a mounting hole that receives the bolt of one first fastening member and a side hole perpendicularly extending from the bottom side of the mounting hole to the outside of the respective second fastening member, and connectors respectively inser