Mitsubishi Electric MSZ-EF18NAW-U1 Service Manual page 24

OPERATION INDICATOR
Abnormal
No. Operation indicator lamp
point
Left lamp lights and lower lamp blinks.
MXZ type
Operation
1
mode
setting
2.5-second OFF
9-5. TROUBLESHOOTING CRITERION OF MAIN PARTS
MSZ-EF09NAW MSZ-EF12NAW
MSZ-EF09NAB MSZ-EF12NAB
MSZ-EF09NAS MSZ-EF12NAS
Part name
Room temperature
thermistor (RT11)
Indoor coil thermistor
(RT12, RT13)
Indoor fan motor (MF)
Vane motor (MV)
OBH736C
Symptom
Outdoor unit
operates but
indoor unit does
not operate.
MSZ-EF15NAW
MSZ-EF15NAB
MSZ-EF15NAS
Check method and criterion
Measure the resistance with a multimeter.
Refer to 9-7. "Test point diagram and voltage", "Indoor electronic control
P.C. board", for the chart of thermistor.
Check 9-6. "Check of indoor fan motor".
Measure the resistance between the terminals with a multimeter.
(Temperature: 50 - 86°F (10 - 30°C))
Color of the lead wire
RED - BLK
Condition
The operation mode of the each indoor unit is
differently set to COOL (includes DRY) and
HEAT at the same time, the operation mode of
the indoor unit that has operated at first has
the priority.
MSZ-EF18NAW
MSZ-EF18NAB
MSZ-EF18NAS
Normal
232 - 268 Ω
24
Remedy
• Unify the operation mode.
Refer to outdoor unit service
manual.
Figure
BLK
ROTOR
BLK
RED
BLK BLK