Mitsubishi Electric MSZ-AY25VGKP-E6 Service Manual page 37

MXZ Type
LED indication
for communication status
Communication status is indicated
by the LED.
Unit status
Blinking: normal communication
Lit: abnormal communication or
not connected
Pattern 1 and 2 is repeatedly displayed
alternately. Each pattern is displayed for
10 seconds.
NOTE: "Lit" in the table below does not
indicate abnormal communication.
Outdoor control P.C. board
LED1 LED2 LED3
Blinking
Pattern
LED 1 LED 2
Unit B
Unit A
1
status
status
Unit C Unit D
2
status status
Unit E
3
status
OBH930
Turn OFF the power supply.
Is there rated voltage in
the power supply?
Yes
Turn ON the power supply.
Is there rated voltage between
outdoor terminal block S1 and
S2?
Yes
Press EMERGENCY OPERATION switch once.
Does the upper lamp of OPERATION
INDICATOR lamp on the indoor unit light up?
<Confirmation of the power to the indoor unit>
LED 3
Yes
Lit
Is serial signal error indicated 6 minutes later?
Not lit
Blinking
Yes
· 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?
Turn OFF the power supply.
Check once more if the indoor/outdoor
connecting wire is not miswiring.
Bridge the outdoor terminal block S2 and
S3. *1
Turn ON the power supply.
Does the LED on the outdoor control P.C.
board repeat "3.6-second-OFF
and 0.8-second-ON quick blinking"?
Yes
Turn OFF the power supply.
Remove the bridge between
outdoor terminal block S2 and S3.
Turn ON the power supply.
Is there amplitude of 10 to 20 V DC
between outdoor terminal block S2
and S3? <Confirmation of serial
signal>
Yes
Is there rated voltage between
indoor terminal block S1 and S2?
<Confirmation of power voltage>
Yes
Replace the indoor electronic control P.C. board.
Be sure to release the failure-mode
recall function after checking.
Check the power
supply.
No
Check the wiring.
No
No
Is there any miswiring,
poor contact, or wire
disconnection of the
No
indoor/outdoor
connecting wire?
· Reinstall either the unit or the light
away from each other.
· Attach a filter on remote control
No
receiving section of the indoor unit.
Yes
*1 Miswiring may damage indoor electronic control
P.C. board during the operation.
Be sure to confirm the wiring is correct before the
operation starts.
Replace the outdoor control P.C. board.
*2
No
(Lit or not lit)
*2 Be careful of the residual
No
Is there any error of the
indoor/outdoor connecting wire,
such as the damage of the wire,
No
intermediate connection, poor
contact to the terminal block?
37
Correct them.
Yes
No
voltage of smoothing capacitor.
Replace the
indoor/outdoor
Yes
connecting wire.
No