Mitsubishi Electric Mr. SLIM MSZ-FA25VA Technical Manual página 370

Resolución de averías
When the left lamp of OPERATION INDICATOR lamp flashes 9-time.
Indoor unit and outdoor unit do not operate.
Check of float sensor
E
Connect the lead wire.
*1 Refer to 9-5. when
float sensor can be checked.
When heating or cooling, room does not get warm or cool.
How to Check mis-wiring or incorrect piping
F
• Mis-wiring or incorrect piping is difficult to determine, because operation is almost normal when all indoor units operate.
During HEAT
When one unit is operated in standard operating temperature, the compressor operates in minimum frequency,
and the room does not warm.
During COOL
When one unit is operated, air coming out is not cold (same as FAN operation), and the room does not cool.
Heat exchanger of the unit not operating freezes. This may cause malfunction of compressor.
Refer to outdoor unit service manual.
370
Turn OFF the power supply and check
connectors CN145 and CN1N1 visually.
Yes
Are the lead wires
disconnected?
No
Disconnect float sensor from CN145 of
indoor electronic control P.C. board.
Measure the resistance between 1 and 2 .
Is the resistance 1Ω or
less? *1
Is there large amount
of water in drain pan?
Turn ON the power supply. Press
EMERGENCY OPERATION switch
(COOL) and perform emergency COOL
operation. Measure the voltage between
CN1N1 1 and 2 .
Is there 230V AC
between CN1N1 1 and
2 ?
Is the drain pump
operating?
Is the drain hose
clogged?
Replace the indoor
electronic control P.C. board.
Are there abnormality in
the soldering part of
connectors?
No
Yes
Replace the indoor
electronic control P.C. board.
No
No
Replace the float sensor.
Yes
Replace the indoor
No
electronic control P.C. board.
Check power supply voltage.
Yes
No
Replace the drain pump.
Yes
Yes
Remove clog from drain
hose.
No
<Only for multi units>
Indoor electronic control P.C. board
CN145
CN1N1
Yes
Solder the connector.