Any incorrect welding operation can lead to plastic deformation and poor switch contact. Users in the use of pin type button switch, signal lamp, due to improper welding damage phenomena have occurred, so please be sure to pay attention to the user in the connection operation is the following: select the appropriate electric iron, high welding speed, recommend the use of 20W electric iron welding within 3 seconds to complete. The soldering flux must be in proper quantity and the switch pin will be turned down as far as possible. Try to use plug line terminal connection to avoid welding connection.