Mitsubishi Electric PURY-P200 Service Handbook page 152

4. Trouble shooting according to the remote controller malfunction and the external input error
(1) In the case of MA remote controller
Phenomena
1 Even if the operation SW on
the remote controller is
pressed, the display remains
unlit and the unit does not
start running.
(Power indicator
appear on the screen.)
Factors
(1) The power for the indoor unit is not
on.
1 The power of the indoor unit is
OFF.
2 The connector on the indoor unit
controller board has come off.
3 The fuse on the indoor unit
does not
controller board has melted.
4 Transformer failure and
disconnected wire of the indoor
unit
(2) The wire for the MA remote
controller is connected incorrectly.
1 Disconnected wire for the MA
remote controller and
disconnected line to the terminal
block.
2 Short circuit of the wire for the
MA remote controller
3 Reversed connection of the wire
for the MA remote controller
4 The wire for the MA remote
controller is connected
incorrectly to the terminal block
for the transmission line (TB5).
5 Reversed connection between
the wire for the MA remote
controller and the power-supply
wire for AC220~240V.
6 Reversed connection inside the
indoor unit between the wire for
the MA remote controller and the
M-NET transmission line.
(3) The number of the MA remote
controllers that are connected to an
indoor unit exceeds the allowable
range (2 units).
(4) The length and the diameter of the
wire for MA remote controller are
out of specification.
(5) Short circuit of the wire for the
remote display output for the
outdoor unit or reversed polarity
connection of the relay.
(6) Indoor unit controller board failure
(7) MA remote controller failure
- 149 -
Checke method & Handling
(a) Check voltage of the MA remote
controller terminal (among 1 to 3).
i) If the voltage is DC8.5-12V, the
remote controller is defective.
ii) If there is no voltage
Check the left described (1) and (3).
If a fault is found, handle the
problem.
If no fault is found, refer to (b).
(b) Remove the wire for the remote
controller from the terminal block
(TB13) on the MA remote controller
for the indoor unit, and check
voltage among 1 to 3.
i) If the voltage is DC8.5-12V
Check the left described (2) and (4).
If a fault is found, handle the
problem.
ii) If there is no voltage
Check the left described (1) again.
If a fault is found, handle the
problem.
If no fault is found, check the wire
for the remote display output (the
relay polarity).
If no further fault is found, replace
the indoor controller board.