Hi.
I have examined the radio and it appears that the original (codeplug) eeprom has reached the end of its life and needs to be replaced with a 24C01 or 24C02 serial eeprom chip.
WA1MIK has made a program that can write eeprom data to the M100 radio but apparently the program is not publicly available anywhere?.
https://www.repeater-builder.com/motorola/r100/r100-eeprom.html
