Mitsubishi Electric Mr.Slim PLA-A24EA7 Service Manual page 26

9-4. TROUBLESHOOTING BY INFERIOR PHENOMENA
Phenomena
(1)Upward/downward vane
performance failure
(2)Receiver for IR wireless remote
controller
OCH640C
Note: Refer to the manual of outdoor unit for the detail of remote
Cause
1 The vane is not downward during defrost-
ing and heat preparation and when the
thermostat is OFF in HEAT mode. (Working
of COOL protection function)
2 Vane motor does not rotate.
• Defective vane motor
• Breaking of wire or connection failure of
connector
3 Upward/downward vane does not work.
• The vane is set to fixed position.
1 Weak batteries of IR wireless remote con-
troller
2 Contact failure of connector (CNB) on IR
wireless remote controller board
(Insert failure)
3 Contact failure of connector (CN90) on
indoor controller board (Insert failure)
4 Contact failure of connector between IR
wireless remote controller board and indoor
controller board
26
controller.
Countermeasure
1 Normal operation (The vane is set to hori-
zontal regardless of remote control.)
2 Check 2 (left).
• Check the vane motor. (Refer to "9-6.
HOW TO CHECK THE PARTS".)
• Check for breaking of wire or connection
failure of connector.
3 Normal operation (Each connector on vane
motor side is disconnected or setting the
fixed vanes by wired remote
controller.)
1 Replace batteries of IR wireless remote
controller.
2–4
Check contact failure of each connector.
If no problems are found of connector,
replace indoor controller board.
When the same trouble occurs even if
indoor controller board is replaced,
replace IR wireless remote controller
board.