Failure Mode Recall Function - Mitsubishi MSZ-FA25VA Service Manual

9-2. 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 disappears, the memorized failure details can be
recalled.
This mode is very useful when the unit needs to be repaired for the abnormality which doesn't recur.
1. Flow chart of the indoor/outdoor unit failure mode recall function
Operational procedure
The cause of abnormality cannot be found because the abnormality doesn't recur.
Setting up the failure mode recall function
Turn ON the power supply.
1 While pressing both OPERATION SELECT
button and TOO COOL button on the remote controller at the same
time, press RESET button.
2 First, release RESET button.
And release the other two buttons since all LCD in operation display
section of the remote controller is displayed after 3 seconds.
W1
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 TOO COOL or TOO
WARM button to adjust the set temperature to 24:.
Does POWER lamp on the indoor
unit blink at the interval of 0.5 seconds?
Blinks: Either indoor or outdoor unit is abnormal.
Beep sounds are emitted at the same timing
of the blinking of POWER lamp. W2
Judgment of indoor/outdoor abnormality
Before blinking, does POWER
lamp stay ON for 3 seconds?
Stays ON for 3 seconds (without beep):
The indoor unit is abnormal.
Check the blinking pattern, and refer to confirm the
abnormal point(9-2.4.).
Make sure to check at least two consecutive blinking cycles. W2
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
1With the remote controller headed towards the indoor unit, press any button
that is not used in this failure mode recall function (e.g. TIMER button) .
OR
1Turn OFF the power supply and turn ON it again.
2Press RESET button of the remote controller.
Deleting the abnormal condition
1After repairing the unit, recall the failure mode again according to
"Setting up the failure mode recall function" mentioned above.
2Press EMERGENCY OPERATION switch so that the memorized
abnormal condition is deleted.
3Release the failure mode recall function according to "Releasing the
failure mode recall function" mentioned above.
Note1.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.
W2. Blinking pattern when the indoor unit is abnormal:
2.5-second OFF
ON
OFF
Repeated cycle
W3.Blinking pattern when the outdoor unit is abnormal:
2.5-second OFF
ON
OFF
Yes
(Blinks)
The outdoor unit is abnormal.
No
Repair the defective parts.
Blinking at 0.5- Blinking at 0.5-
second interval second interval
2.5-second OFF
Beeps
Repeated cycle
Blinking at 0.5-
3-second ON second interval
No beep Beeps
Repeated cycle
No
Indoor unit is normal.
(OFF)
There is a possibility that the plasma or outdoor unit is abnormal.
Confirm the presence of abnormality according to the flow chart of the
the prasma unit or detailed outdoor unit failure mode recall function.
Yes
The outdoor unit is abnormal.
Check the blinking pattern, and refer to confirm the abnormal point.
Make sure to check at least two consecutive blinking cycles. W3
•As for outdoor unit MUZ type, refer to service manual OB372.
As for outdoor unit MXZ type, refer to service manual OB377.
Beeps Beeps
Repeated cycle
2.5-second OFF 3-second ON
No beep
Repeated cycle
14
1 While pressing both OPERATION SELECT
button and TOO COOL button on the
remote controller at the same time,
press RESET button.
2 First, release RESET button.
And release the other two buttons since all LCD
in operation display section of the remote controller
is displayed after 3 seconds.
W1. Regardless of normal or abnormal, a short
beep is emitted once as the signal is received.
Blinking at 0.5-
second interval
Beeps
Repeated cycle