Mitsubishi Electric PKA-A24KA8 Service Manual page 19

Phenomena
(3)Upward/downward vane
performance failure
(4)Receiver for wireless remote
controller
TCH115A
Note: Refer to the outdoor unit's service manual for the detail of remote controller.
Cause
The vane is not downward during defrosting and heat
preparation and when the thermostat is OFF in HEAT
mode. (Working of COOL protection function)
Vane motor does not rotate.
• Defective vane motor
• Breaking of wire or connection failure of connector
Upward/downward vane does not work.
• The vane is set to fixed position.
Weak batteries of wireless remote controller
Contact failure of connector (CNB) on wireless remote
controller board (Insert failure)
Contact failure of connector (CN90) on indoor control-
ler board (Insert failure)
Contact failure of connector between wireless remote
controller board and indoor controller board
19
Countermeasure
Normal operation (The vane is set to hori-
zontal regardless of remote control.)
Check (left).
• Check the vane motor. (Refer to 9-6.
HOW TO CHECK THE PARTS.)
• Check for breaking of wire or connection
failure of connector.
Normal operation (Each connector on
vane motor side is disconnected or setting
the fixed vanes by wired remote
controller.)
Replace batteries of wireless remote con-
troller.
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 wireless remote controller
board.