Mitsubishi Electric PCA-A24KA Service Manual page 22

Phenomena
(2)LED2 on indoor controller board
is blinking.
(3)Upward/downward vane
performance failure
(4)Receiver for wireless remote
controller
Cause
• When LED1 on indoor controller board is also blinking.
Connection failure of indoor/outdoor unit connecting
wire
• When LED1 is lit.
Miswiring of remote controller wires
Under twin indoor unit system, 2 indoor units are
wired together.
Refrigerant address for outdoor unit is wrong or not
set.
Under grouping control system, there are some units
whose refrigerant address is 0.
Short-cut of remote controller wires
Defective remote controller
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 con-
troller board (Insert failure)
Contact failure of connector between wireless remote
controller board and indoor controller board
Note: Refer to the manual of outdoor unit for the detail of remote
controller.
Check indoor/outdoor unit connecting wire
for connection failure.
Check the connection of remote con-
troller wires in case of twin indoor unit
system. When 2 indoor units are wired in
one refrigerant system,
connect remote controller wires to one of
those units.
Check the setting of refrigerant address
in case of grouping control system.
If there are some units whose refrigerant
addresses are 0 in one group, set one of
the units to 0 using SW1 (3-6) on outdoor
controller circuit board.
• When LED2 is blinking, check the short-
• When LED2 is lit, connect remote
Normal operation (The vane is set to
horizontal regardless of remote control.)
Check
• Check the vane motor. (Refer to "How
• Check for breaking of wire or connec-
Normal operation (Each connector on
vane motor side is disconnected or set-
ting the fixed vanes by wired remote
controller.)
Replace batteries of wireless remote con-
troller.
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22
Countermeasure
Remove remote controller wires and
check LED2 on indoor controller board.
cut of remote controller wires.
controller wires again and:
if LED2 is blinking, remote controller
is defective; if LED2 is lit, connection
failure of remote controller terminal
block etc. has returned to normal.
(left).
to check the parts".)
tion failure of connector.
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.