Mitsubishi Electric MSZ-FD25VA Service Manual page 23

4. Indoor unit failure mode table
POWER lamp
Not lighted
Room temperature
1-time flash
thermistor
every 0.5-second
2-time flash
Indoor coil thermistor
2.5-second OFF
3-time flash
Serial signal
2.5-second OFF
11-time flash
Indoor fan motor
2.5-second OFF
12-time flash
Indoor control system
2.5-second OFF
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 supply
1-time flash
control
2-time flash Spark discharge
Abnormal electric
3-time flash
discharge error 1
Abnormal electric
4-time flash
discharge error 2
5-time flash PLASMA DEODORIZING
NOTE1 : Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-4.).
NOTE2 : 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.
NOTE3 : When POWER lamp flashes 1-time or 2-time, Please perform PLASMA operation check (Refer to 10-2.3).
Abnormal point
(Failure mode)
Normal
The room temperature thermistor short
or open circuit is detected every 8 seconds
during operation.
The indoor coil thermistor short or open
circuit is detected every 8 seconds during
operation.
The serial signal from outdoor unit is
not received for 6 minutes.
The rotational frequency feedback signal is
not sent out for 12-seconds after indoor fan
motor is operated.
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 3(+) and 2(GND)
on the PLASMA POWER P.C.board falls
below 1.6 V(spark discharge judgment
voltage).
The voltage between CN1 3(+) and 2(GND)
on the PLASMA POWER P.C.board falls by
0.9 V below the normal voltage value (3 V).
The voltage between CN1 3(+) and 2(GND)
on the PLASMA POWER P.C.board falls
significantly. (0.4 V / 0.5 ms)
The voltage between CN1 3(+) and 2(GND)
on the PLASMA POWER P.C board rises
above the normal voltage value (3 V).
Condition
—
Refer to the characteristics of the room
temperature thermistor (10-7.).
Refer to the characteristics of the main
indoor coil thermistor, the sub indoor coil
thermistor (10-7.).
Refer to 10-6.D "How to check miswiring
and serial signal error".
Refer to 10-6.A "Check of indoor fan
motor".
Replace the indoor electronic control
P.C. board.
Replace the indoor electronic control
P.C.board.
Refer to 10-6.F"Check of PLASMA
operation".
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Correspondence
—
Correspondence