Mitsubishi Electric Mr. Slim MSZ-FE09NA Service Manual page 23

2. Indoor unit failure mode table
POWER lamp Abnormal point
Upper lamp (Failure mode)
Not lighted Normal
1-time fl ash every Room temperature
0.5-second thermistor
2-time fl ash Indoor coil thermis-
2.5-second OFF tor
3-time fl ash
Serial signal
2.5-second OFF
11-time fl ash
Indoor fan motor
2.5-second OFF
12-time fl ash Indoor control
2.5-second OFF system
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (9-4.).
POWER lamp: MSZ-FE09/12NA
Upper lamp: MSZ-FE18NA
Condition
—
The room temperature thermistor short or open
circuit is detected every 8 seconds during op-
eration.
The indoor coil thermistor short or open circuit
is detected every 8 seconds during operation.
The serial signal from outdoor unit is not re-
ceived for a maximum of 6 minutes.
The rotational frequency feedback signal is not
emitted for 12 seconds after the indoor fan mo-
tor is operated.
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
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.
signal error".
Refer to 9-6.
Replace the indoor electronic control P.C. board.
23
Remedy
—
"How to check miswiring and serial
"Check of indoor fan motor".