An electrical connector for electrically connecting a terminal to a cord of a peripheral device, the electrical connector including a plug member, a lever arm pivotally attached to the plug member, and a biasing member. A signal is monitored over time by allocating a current signal quality characterization to the signal, selected from at least two such signal quality characterizations, such as perfect time, errored time and unavailable time. An alignment hole, an alignment pin inserted into the alignment hole, a guide groove having one opened side, and a guide protrusion fitted into the guide groove are formed in the flexible printed circuit and the actuator arm, and the alignment hole and the alignment pin are fixed to each other through a soldering process. A first reciprocal connector disposed in the first end of the adapter plug is configured to mate with the first connector.