Mitsubishi Electric MSZ-GA35VA Service Manual page 13

2. Indoor unit failure mode table
NOTE:Blinking patterns of this mode differs from the ones of Troubleshooting check table(9-4.).
Left lamp of
OPERATION
INDICATOR lamp
Not lighted
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 error
2.5-second OFF
11-time flash
Indoor fan motor
2.5-second OFF
12-time flash
Indoor control system
2.5-second OFF
Abnormal point
(Failure mode)
Normal
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 12-second the
indoor fan operation.
When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
Detection method
–
13
Check point
–
Refer to the characteristics of the room
temperature thermistor (9-7.).
Refer to the characteristic of the main
indoor coil thermistor, the sub indoor coil
thermistor (9-7.).
Refer to 9-6.D "How to check miswiring
and serial signal error".
Refer to 9-6.A "Check of indoor fan
motor".
Replace the indoor electronic control
P.C. board.