The MC602 is an intercom device created by M&S. An intercom is used to allow wireless communication between people in different areas. This particular model can be used for room-to-room communication as well as to find out who's at your front door before you answer it. If the device begins to malfunction, one of the quickest ways to solve the issue is to reset it. A reset function is built into the device to simplify this process.
Remove the face panel of the device.
Locate the word "Reset" to the right of the 12 buttons. Touch the four silver solder dots next to "Reset."
Wait for the device to finish the reset process -- once it has, the display should flash "12:00."
Reset the settings according to your preferences to begin using the device again. Replace the face panel.