Troubleshooting - Mitsubishi MCFH-13NV Service Manual

11

TROUBLESHOOTING

MCFH-13NV - MCFH-24NV -
E4
MCFH-18NV -
E3
11-1. Cautions on troubleshooting
11-1-1. Before troubleshooting, check the followings:
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for mis-wiring.
11-1-2. Take care the followings during servicing.
1) Before servicing the air conditioner, be sure to first turn off the remote controller to stop the main unit, and then after
confirming the horizontal vane is closed, turn off the breaker.
2) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
3) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
11-1-3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.
2) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and
the components for bursting and discoloration.
3) When troubleshooting, refer to the flow chart and the check table on page 43, 44.
11-1-4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
1 Remove the front lid and insert batteries.Then reattach the front lid.
2 Press the RESET button with tip end of ball point pen or the like, and then use the remote controller.
NOTE : If the RESET button is not pressed, the remote controller may not operate correctly.
MUCFH-13NV -
E3
MUCFH-18NV -
Insert the negative pole
of the batteries first.
Check if the polarity of
the battereis is correct.
MUCFH-24NV -
E4
E3
RESET button
42
E3