Why does my IC-M91D VHF/DSC Handheld buzz?

Your IC-M91D is buzzing because your 'Inactivity Timer' has gone off. If you look in the manual under the heading 'Inactivity Timer' you will find that if you leave the radio on in a particular menu and don't use it for a predetermined amount of time (settable from 1 to 10 minutes and default to 10 minutes) the radio will buzz/chirp for 10 seconds before returning back to the main screen displaying channel and GPS info. If in that 10 seconds you pick up the radio or press a button it will stay in the menu you had left it. If you do not touch the radio within this time it will revert to the main screen. This feature can be turned off if not required, so please consult your user manual for more details.

NB There is also a DSC menu 'Inactivity timer' that works in the same way and can be set up to a time limit of 15 minutes.

04/10/2012