6 – 3
ALARM
CATEGORY
ALARM
LED DISPLAY
ALARM 10 12 15 17 20
PROP HSD UTL NLQ
REMARKS TROUBLESHOOTING
MAIN
CONTROL
ALARM
FIRMWARE
DETECTION
ALARM
SERIAL
INTERFACE
ALARM
MPU internal
RAM alarm
Program ROM
alarm
RAM on Control
Board alarm
EEPROM alarm
WDT (Watch Dog
Timeout) alarm
NMI signal alarm
BRK instruction
alarm
MPU internal
RAM alarm
ROM alarm
RAM on I/F board
alarm
I/F not mounted
Read/write error
Check sum error
Read/write error
No reaction when MPU
reads data
MPU is locked up and it
ios reset after 65ms.
NMI port of MPU is
kept low level.
FFFF data is detected
due to MPU locked up.
Read/write error
Check sum error
Read/write error
No reaction from
serial I/F board
Replace Control/
Power Supply Board
Replace ROM or Con-
trol/Power Supply Board
Replace Control/
Power Supply Board
Replace Control/
Power Supply Board
Turn the power OFF and
ON or replace Control/
Power Supply Board
Turn the power OFF and
ON or replace Control/
Power Supply Board
Replace ROM or Con-
trol/Power Supply Board
Replace I/F Board
Replace ROM on I/F
board or I/F Board
Replace I/F Board
Replace I/F Board or
Control Board.
: LED Blink (200ms ON, 200ms OFF)
: LED Lights up
(3) Fatal Alarm
Table 6.3 (1/2)