You attempt to program a new MMSI into a VHF radio with an existing MMSI. The radio will not accept the entry. What is the best course of action to correct this problem?
You must RESET the DSC memory by holding down two buttons as described in the user manual.
You can never change a number, once one is already programmed.
Re-register the old MMSI with the new owner and make no programming changes to the radio.
Contact the manufacturer for action to clear the MMSI memory and accept the new number.