Indoor Unit - Mitsubishi Electric MSZ-FD25VA 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. PLASMA operation failure mode table
Abnormal point
POWER lamp
(Failure mode)
PLASMA power
1-time fl ash
supply control
2-time fl ash Spark discharge
Abnormal electric
3-time fl ash
discharge error 1
Abnormal electric
4-time fl ash
discharge error 2
PLASMA
5-time fl ash
DEODORIZING
NOTE 1: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-4.).
NOTE 2: As soon as an abnormality is detected, PLASMA operation goes OFF, therefore measuring instrument which records
the voltage wave is required in order to perform the above mentioned voltage measurement.
NOTE 3: When POWER lamp flashes 1-time or 2-time, please perform PLASMA operation check (Refer to 10-2.3).
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
PLASMA power supply cannot be turned OFF
even if the PLASMA operation is turned OFF
with the remote controller.
The voltage between CN1 (+) and
on the PLASMA POWER P.C. board falls below
1.6 V (spark discharge judgment voltage).
The voltage between CN1 (+) and
on the PLASMA POWER P.C. board falls by
0.9 V below the normal voltage value (3 V).
The voltage between CN1 (+) and
on the PLASMA POWER P.C. board falls
signifi cantly. (0.4 V / 0.5 ms)
The voltage between CN1 (+) and
on the PLASMA POWER P.C board rises
above the normal voltage value (3 V).
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.
Replace the indoor electronic control P.C. board.
(GND)
(GND)
Refer to 10-6. "Check of PLASMA operation".
(GND)
(GND)
23
Correspondence
—
"How to check miswiring and serial
"Check of indoor fan motor".
Correspondence