Troubleshooting - Mitsubishi Electric MSH-18NV Service Manual

10

TROUBLESHOOTING

MSH-18NV -
E4
10-1. Cautions on troubleshooting
1. Before troubleshooting, check the following:
(1) Check the power supply voltage.
(2) Check the indoor/outdoor connecting wire for mis-wiring.
2. Take care the following 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 and / or disconnect the power plug.
(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.
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 discolouration.
(3) When troubleshooting, refer to the flow chart on page 22 and the check table on page 23.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, the remote controller can not be repaired only by the battery replacement. To operate the remote controller
normally, discharge the remote controller in the following order.
This remote controller has the RESET button. After refilling new batteries, press the RESET button with tip end of ball
point pen or the like, and then use the remote controller.
NOTE: INFORMATION FOR MULTI SYSTEM AIR CONDITIONER
(OUTDOOR UNIT : MXZ-32NV-
Multi system air conditioner (Outdoor unit: MXZ-32NV-
indoor units with one outdoor unit.
According to the capacity, two or more units can operate simultaneously.
•When you try to operate two or more indoor units with one outdoor unit simultaneously, one for the cooling and the
other for heating, the operation mode of the indoor unit that operates earlier is selected. The other indoor units that
will start the operation later cannot operate, indicating as shown in the figure below. In this case, please set all the
indoor units to the same operation mode.
•When indoor units starts the operation while the defrosting of outdoor unit is being done, it takes a few minutes
(max. 10 minutes) to blow out the warm air.
•In the heating operation, though indoor unit that does not operate may get warm or the sound of refrigerant flowing
may be heard, they are not malfunction. The reason is that the refrigerant continuously flows into it.
Housing point
Lead wiring
, MXZ-32NV-
E1
RESET button
,
MXZ-32RV- )
E2 E1
,
, MXZ-32NV- MXZ-32RV-
E1 E2
Operation Indicator
21
) can connect two or more
E1
lighting
flashing