Troubleshooting - Mitsubishi Electric PKH18FK Technical & Service Manual

TROUBLESHOOTING

9
1.TROUBLE IN TEST RUN
Symptom
The display "CENTRALLY
CONTROLLED" on remote
controller does not disap-
pear.
When remote controller
POWER button is turned
ON, the check code
"EO"appears.
When remote controller
POWER button is turned
ON, operating display
appears, but disappears
soon.
Despite turning POWER
button ON, the remote
controller display does not
appear.
Cause
1) Wrong address setting of remote con-
troller/indoor controller board.
2) Timer adapter is connected to the
remote controller.
3) Signal transmission error between
indoor unit and remote controller.
1) Signal transmission error between
indoor unit and remote controller
1) Short circuit of indoor/outdoor connect-
ing wire
2) Short circuit of transmission wire.
3) Short circuit of drain sensor heater cir-
cuit.
4) Wrong operation of remote controller
due to noise wave emitted by other
appliances.
1) Damaged remote controller.
2) Short circuit of transmission wire.
3) Bad contact of indoor CN40.
4) CN40 is attached to a sub unit.
5) Damaged transformer.
6) Bad contact of CN4T.
7) Blown fuse.
8) Circuit breaker OFF.
Check points
1) Check the address setting of remote controller
and indoor controller.
2) Make sure the timer adapter is used correctly.
3) 1 Turn another remote controller's DIP SW17-
7 ON to make it sub controller.
2 Connect the sub controller to the unit, and
turn circuit breaker ON.
If the display "centrally controlled" disap-
pears, replace the original remote controller.
If the display remains the same, replace the
indoor controller board.
1) 1 Connect a sub remote controller.
2 Turn circuit breaker ON.
If the display "centrally controlled" remains,
replace the indoor controller board.
3 If the display disappears, turn the remote
controller POWER button ON and check as
follows.
Remote controller Sub remote controller
1 Operating Display EO Display
2 Operating Display Operating Display
3 NO Display EO Display
4 NO Display Operating Display
1), 2) Check the wire
3) Measure the resistance of the drain sensor
connector CN50 1 - 3. Normal resistance
should be 82Ω.
4) Turn the circuit breaker OFF, and then turn
ON.
If the remote controller remains abnormal,
despite the above measures, replace the indoor
controller board.
1) Measure the voltage between terminals of
remote controller. If no voltage, remove the
wire from the terminals and measure the volt-
age between wires. If the voltage is between
6VDC and 12V, replace the remote controller.
2) ~ 8) Check each point.
If it is not defective, replace the indoor
controller board.
Malfunction
Malfunction of
indoor Unit
Malfunction of
Remote controller
Malfunction of
indoor Unit and
Remote Controller
Malfunction of
Remote controller
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