It more than likely needs a new EEPROM chip, that is probably the only thing wrong with the board. Its the only chip in a socket on the PCB.
However... Personally I would upgrade panel and keypad to something like a Scantronic 9651 and get all the benefits of fob operation and an Lcd keypad.
However 2... If your existing system is a 9800, the rest of the system probably needs updating too, especially if there have been any changes to the construction and use of the property since installation.