User update: Press the FRONT (INFO + DISPLAY) Key for 3 sec
Factory Reset : Press the FRONT (INFO+ZONE) Key for 3 sec
Version display : Press the FRONT (INFO+DIRECT) Key for 3 sec
Volume check : Press the FRONT (MENU+DIRECT) Key for 3 sec
FM Stereo mode : Press the FRONT (OK+DIRECT) key for 3 sec
