Troubleshooting - Mitsubishi Electric MSH-07NV Service Manual

10

TROUBLESHOOTING

MSH-07NV - MSH-09NV -
E1
MSH-18NV - MSH-24NV -
E1
MSH-09NV - MSH-12NV -
E2
MSH-24NV - MSH-18NV -
E2
10-1 Cautions on troubleshooting
10-1-1 Before troubleshooting, check the followings:
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for mis-wiring.
10-1-2 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.
10-1-3 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 on page 48 and the check table on page 49.
10-1-4 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 con-
troller 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.
A A
There are two kind of remote controllers. A A type has the RESET button at the back, and B B type does it on the
front. How to use the two buttons are given in the Instruction Manual.
MSH-12NV -
E1
MSH-07NV -
E1
MSH-18NV -
E2
E3
Housing point
Lead wiring
RESET button
E1
E2
E2
B B
RESET button
47