Failure Mode Recall Function - Mitsubishi Electric Mr.Slim MUZ-A09NA Service Manual

10-2. 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 (10-3.) 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 both OPERATION SELECT button and TOO COOL button on the
remote controller at the same time, press RESET button.
First, release RESET button.
And release the other two buttons after all LCD in operation display section of the
remote controller is displayed after 3 seconds.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature
is displayed) with the remote controller headed towards the indoor unit.
Does the left lamp of OPERATION INDICATOR lamp on the
indoor unit blink at the interval of 0.5 seconds?
Blinks: Either indoor or outdoor unit is abnormal. Beep is emit-
ted at the same timing as the blinking of the left lamp
of OPERATION INDICATOR lamp.
Judgment of indoor/outdoor abnormality
Before blinking, does the left lamp of OPERATION INDICA-
TOR lamp stay ON for 3 seconds?
Stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.
The indoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the indoor unit
failure 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.
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 OPERATE/STOP (ON/OFF) 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 once it's 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
Repeated cycle
3.Blinking pattern when the outdoor unit is abnormal:
2.5-second OFF 3-second ON
ON
OFF
2
Yes
(Blinks)
No
Repair the defective parts.
2.5-second OFF
Beeps
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 can not be recalled with this way.
No
Confi rm if outdoor unit is abnormal according to the detailed outdoor
(OFF)
unit failure mode recall function. (Refer to 10-2.2)
Yes
The outdoor unit is abnormal.
Check the blinking pattern, and confi rm the abnormal point with the
outdoor unit failure mode table. (Refer to 10-2.3)
2 Make sure to check at least two consecutive blinking cycles.
Blinking at 0.5-
second interval
Beeps
Repeated cycle
2.5-second OFF 3-second ON
No beep
Repeated cycle
39
This figures show about MSZ-A09/12/15/17.
1. Regardless of normal or abnormal condition, a short
beep is emitted once the signal is received.
Beeps
Blinking at 0.5-
second interval
Beeps
3
Repeated cycle