Troubleshooting - Mitsubishi Electric MUCFH-GA35VB Service Manual

11

TROUBLESHOOTING

MUCFH-GA35VB
11-1. 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 service.
(1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and then after
confirming the horizontal vane has completely closed, turn OFF the breaker.
(2) Be sure to unplug the power cord before removing the air inlet grille, the front panel, the cabinet, the top panel and
the electronic control P.C. boards.
(3) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
(4) 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 discoloration.
(3) When troubleshooting, refer to 11-2. "Instruction of troubleshooting".
MUCFH-GA50VB MUCFH-GA60VB
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