Mitsubishi Electric MSZ-GA50VA Service Manual page 14

2. Indoor unit failure mode table
Left lamp of
Abnormal point
OPERATION
(Failure mode)
INDICATOR lamp
Not lighted Normal
Room temperature
1-time flash
thermistor
every 0.5-second
2-time flash
Indoor coil thermistor
2.5-second OFF
3-time flash
Serial signal
2.5-second OFF
11-time flash
Indoor fan motor
2.5-second OFF
12-time flash
Indoor control system
2.5-second OFF
NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (9-4.).
Condition
–
When the room temperature thermistor
short or open circuit is detected every 8
seconds during operation.
When the indoor coil thermistor short or
open circuit is detected every 8 seconds
during operation.
When the serial signal from the outdoor unit is
not received for a maximum of 6 minutes.
When the rotational frequency feedback
signal is not emitted during the 12-seconds
indoor fan operation.
When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
14
Correspondence
–
Refer to the characteristics of the room
temperature thermistor (9-7.).
Refer to the characteristics of the main
indoor coil thermistor, the sub indoor coil
thermistor (9-7.).
Refer to 9-6.D "How to check mis-wiring
and serial signal error".
Refer to 9-6.A "Check of indoor fan
motor".
Replace the indoor electronic control
P.C. board.