25
9-4. TROUBLESHOOTING CHECK TABLE
Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and detected an abnormality of the following condition (the first detection after the
power ON), the indoor fan motor turns OFF and OPERATION INDICATOR lamp blinks.
OPERATION INDICATOR
Blinking
Not lit
No. Abnormal
point
Operation indicator lamp
Symptom
Condition
Remedy
1
Indoor coil
thermistor
Upper lamp blinks.
2-time blink
2.5-second OFF
Indoor unit and
outdoor unit do
not operate.
The indoor coil or the room temperature ther-
mistor is short or open circuit.
• Refer to the characteristics of
indoor coil thermistor, and the
room temperature thermistor
(9-7.).
Room tem-
perature
thermistor
2 Indoor fan
motor
Upper lamp blinks.
3-time blink
2.5-second OFF
The rotational frequency feedback signal is
not emitted during the indoor fan operation.
• Refer to 9-6. "Check of in-
door fan motor".
3 Indoor con-
trol system
Upper lamp blinks.
4-time blink
2.5-second OFF
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
• Replace the indoor electronic
control P.C. board.
4
*1
Refrigerant
circuit
*2 on 9-3
Upper lamp blinks.
14-time blink
2.5-second OFF
The unit has been pumped down for a long
time.
• Check the stop valve.
The refrigerant amount is low.
• Check the connections and the
refrigerant amount for any leak-
age.
The unit is short cycling.
• Check for short cycle.
If any problem is found, provide
some space for air path around
the outdoor unit.
The outdoor fan motor locks up.
• Check that the connecting ca-
ble of the outdoor fan motor is
properly connected.
• Check the resistance value
of the outdoor fan motor.
If any problem is found, replace
the outdoor fan motor.
An abnormality of the indoor thermistors is
detected.
• Refer to “TEST POINT DIA-
GRAM AND VOLTAGE” on the
service manual of indoor unit
for the characteristics of the
thermistors. (Do not start the
operation again without repair
to prevent hazards.)
*1. When the trouble indicated with 14-time blink occurs, turn off the main power supply. Otherwise, the operation indicator lamp
may blink again even if the power is turned off and on using a remote controller.
Operation Indicator lamp
The operation indicator lamp is at the right side of the indoor unit.
•The following indication applies regardless of shape of the indication.
MS-CP13VA MS-CP18VA MS-CP24VA
OBH782A
