Indoor Unit - Mitsubishi Electric MSZ-FH25VE - E1 Service Manual

4. Indoor unit failure mode table
Abnormal point
POWER lamp
(Failure mode)
Not lighted Normal
1-time fl ash every Room temperature
0.5-second thermistor
Indoor coil
2-time fl ash
2.5-second OFF
thermistor
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 (10-4.).
5. AIR PURIFYING power failure mode table
Abnormal point
POWER lamp
(Failure mode)
AIR PURIFYING
1-time flash
power control
Electrode
2-time flash
(Spark discharge)
Electrode
(
Abnormal electric
3-time flash
discharge error 1
Electrode
(
Abnormal electric
4-time flash
discharge error 2
AIR PURIFYING
5-time flash
power
NOTE1 : Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-4.).
NOTE2 : As soon as an abnormality is detected, AIR PURIFYING power goes OFF, therefore measuring instrument which
records the voltage wave is required in order to perform the above mentioned voltage measurement.
6. Operation check on i-see SENSOR
While recalling the failure details, set the temperature to 19°C to perform the simple check on the i-see SENSOR.
Place your hand over the i-see SENSOR, and the buzzer will beep at 1 second intervals. (Normal detection temperature
range is 34 to 39°C.)
If the buzzer does not beep, check for disconnection of the connectors.
Set the temperature to 23°C to exit the simple check mode on the i-see SENSOR.
Abnormal point
POWER lamp
(Failure mode)
6-time fl ash i-see SENSOR
OBH623A
Condition
—
The room temperature thermistor short or
open circuit is detected every 8 seconds dur-
ing operation.
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 during the 12 seconds the indoor fan
operation.
It cannot properly read data in the nonvolatile
memory of the indoor electronic control P.C.
board.
Condition
When AIR PURIFYING power cannot be turned OFF
even if the AIR PURIFYING operation is turned OFF
with the remote controller.
When the voltage between CN1T1
on the electronic P.C. board falls below 1.3V
(spark discharge judgment voltage).
When the voltage between CN1T1
)
on the electronic P.C. board falls by 1.2V below
the normal voltage value (2.5V).
When the voltage between CN1T1
)
on the electronic P.C. board falls significantly.
(0.4V / 0.5ms)
When the voltage between CN1T1
on the electronic P.C. board rises above 3V.
Condition
Poor contact in i-see SENSOR wiring
Failure in loading corrected data of i-see
SENSOR
Refer to the characteristics of the room temperature
thermistor (10-7.).
Refer to the characteristics of the main indoor coil ther-
mistor, the sub indoor coil thermistor (10-7.).
Refer to 10-6.
signal error".
Refer to 10-6.
Replace the indoor electronic control P.C. board.
(+) and (GND)
Refer to 10-6.
(+) and (GND)
(+) and (GND)
(+) and (GND)
Check for disconnection of the connectors.
23
Remedy
—
"How to check miswiring and serial
"Check of indoor fan motor".
Remedy
"Check of AIR PURIFYING power".
Remedy