Mitsubishi Electric MUZ-LN25VG Service Manual page 34

12-2. FAILURE MODE RECALL FUNCTION
Outline of the function
This air conditioner can memorize the abnormal condition which has occurred once.
Even though LED indication listed on the troubleshooting check table (12-3.) disappears, the memorized failure details can be recalled.
1. Flow chart of failure mode recall function for the indoor/outdoor unit
Operational procedure
The cause of abnormality cannot be found because the abnormality does not recur.
Setting up the failure mode recall function
Turn ON the power supply.
<Preparation of the remote controller>
While pressing OPERATION SELECT button and TEMP
controller at the same time, press RESET button.
First, release RESET button.
Hold down the other 2 buttons for another 3 seconds. Make sure that the indicators on
the LCD screen shown in the right fi gure are all displayed. Then release the buttons.
Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature
is displayed) with the remote controller headed towards the indoor unit.
Does POWER lamp on the indoor unit blink at the interval of
0.5 seconds?
Blinks: Either indoor or outdoor unit is abnormal. Beep is
emitted at the same timing as the blinking of POWER
lamp. 2
Judgment of indoor/outdoor abnormality
Before blinking, does POWER lamp stay ON for 3 seconds?
When it stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.
The indoor unit is abnormal.
Check the blinking pattern, and identify the abnormal point by referring to the
indoor unit failure recall mode table. (Refer to indoor unit service manual.)
Make sure to check at least two consecutive blinking cycles.
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
Turn OFF the power supply and turn it ON again.
Press RESET button of the remote controller.
Repair the failure parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function" mentioned above.
Press STOP/OPERATE (OFF/ON) button of the remote controller (the set temperature is displayed)
with the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function"
mentioned above.
NOTE: 1. Make sure to release the failure mode recall function after it is set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
2. Blinking pattern when the indoor unit is abnormal:
Blinking at 0.5-
second interval
2.5-second OFF
ON
OFF
Beeps
Repeated cycle
3.Blinking pattern when the outdoor unit is abnormal:
2.5-second OFF 3-second ON
ON
OFF
OBH767
button on the remote
1. Regardless of normal or abnormal condition,
a short beep is emitted once the signal is
received.
Yes
(Blinks)
No
2
Blinking at 0.5-
second interval
2.5-second OFF
Repeated cycle
Blinking at 0.5-
second interval
No beep Beeps
Repeated cycle
1
Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnor-
malities that cannot be recalled with this way.
No
Check if outdoor unit is abnormal according to the detailed outdoor unit
(OFF)
failure mode recall function. (Refer to 12-2.2)
Yes
The outdoor unit is abnormal.
Check the blinking pattern, and identify the abnormal point by referring
to the outdoor unit failure recall mode table. (Refer to 12-2.3)
Make sure to check at least 2 consecutive blinking cycles.
4 The information regarding whether the connected
outdoor unit is a low-standby-power model or a non-
low-standby-power model will also be initialized.
(Default= compatible with a low-standby-power
4
model)
Beeps Beeps
Repeated cycle
2.5-second OFF 3-second ON
No beep
Repeated cycle
34
MSZ-LN25/35VG
MSZ-LN50/60VG
3
Blinking at 0.5-
second interval
Beeps
Repeated cycle