Troubleshooting; Before Troubleshooting - Mitsubishi Electric MUZ-FS06NA Service Manual

10

TROUBLESHOOTING

MUZ-FS06NA MUZ-FS06NAH MUZ-FS09NA MUZ-FS09NAH MUZ-FS12NA MUZ-FS12NAH
MUZ-FS15NA MUZ-FS15NAH MUZ-FS18NA MUZ-FS18NAH
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 miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, then after con-
firming the horizontal vane is closed, turn off the breaker and/or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
3) When removing the electrical parts, be careful of the residual voltage of smoothing capacitor.
4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
5) When connecting or disconnecting the connectors, hold the connector housing. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) Check if the OPERATION INDICATOR lamp on the indoor unit is blinking on and off to indicate an abnormality. To make
sure, check how many times the OPERATION INDICATOR lamp is blinking on and off before starting service work.
2) Before servicing, verify that all connectors and terminals are connected properly.
3) When the electronic control P.C. board seems to be defective, check for disconnection of the copper foil pattern and
burnt or discolored components.
4) Refer to 10-2 and 10-3.
OBH873
<Incorrect>
<Correct>
Lead wiring
Connector housing
25