Mitsubishi Electric MUZ-HA VF Series Service Manual page 38

HR60/71
Is there rated voltage between outdoor terminal block S1 and S2?
Wait for 2 or more minutes after the power supply is turned on.
Touch S2 and S3 with multimeter probes and start the emergency operation.
When the emergency operation starts, does the rated voltage occur for
2 seconds between indoor terminal block S2 and S3?
Does the indoor upper lamp of OPERATION
INDICATOR lamp blink continuously 6 minutes
after the emergency operation starts?
Does the outdoor LED blink 6
times?
Does DC (6 V or more) occur
between indoor terminal block S2
and S3?
Replace the indoor power P.C.
board.
OBH822H
Turn the power supply OFF.
Is there rated voltage in the power supply?
Yes
Check for incorrect indoor-outdoor connecting wiring.
• Turn OFF inverter-controlled lighting
equipment.
• Turn OFF the power supply and then turn ON
again.
• Press the emergency operation switch.
Is serial signal error indicated 6 minutes
later?
Yes
Turn the power supply ON.
Yes
Yes
No
Yes
No
Yes
No
Yes
Check the power supply.
No
• Reinstall either the unit or the light away from
each other.
No
• Attach a filter on remote control receiving section
of the indoor unit.
No
No
Does the outdoor LED light up?
Yes
Confirm that the thermostat is OFF
and wiring is not loose.
Replace the outdoor inverter P.C. board.*1
Replace the outdoor inverter P.C. board.*1
*1 Electric charge may remain immediately
after the power supply is turned OFF.
Perform the procedure after 3 minutes.
38
Check for miswiring, broken wires, and loose
wire connection between the power supply and
outdoor terminal block S1 and between the
power supply and outdoor terminal block S2.
Replace the indoor
power P.C. board.
No