Mitsubishi Electronics Troubleshooting Guide for MSZ-FD25VA Air Conditioner: Solutions and Maintenance Tips

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10-6. TROUBLESHOOTING FLOW

POWER lamp flashes 3-time.

Indoor fan does not operate.

A Check of indoor fan motor

The indoor fan motor error has occurred, and the indoor fan doesn't operate.

Turn OFF the power supply.

Is there any foreign matter that interferes the rotation of the line flow fan?

Yes

Remove the foreign matter and adjust the line flow fan.

No

Pay careful attention to the high voltage on the fan motor connector CN211.

Turn ON the power supply, wait 5 seconds or more, and then press EMERGENCY OPERATION switch.

Measure the supply voltage as follows within 12 seconds after EMERGENCY OPERATION switch is pressed.

If more than 12 seconds passes by, turn OFF the power supply and turn ON it again, then measure the voltage. w

1.Measure the voltage between CN211 1(+) and 3(-). 2.Measure the voltage between CN211 5(+) and 3(-).

wIf more than 12 seconds passes after EMERGENCY OPERATION switch is pressed, the voltage mentioned above 2 goes 0 VDC although the indoor electric control P.C. board is normal.

Is there 325 VDC between

 

 

 

CN211 1 (+) and 3 (-), and does

 

 

 

the voltage between CN211 5(+)

Yes

 

and 3(-) rise to the range of 3 to 6

 

 

Replace the indoor fan motor.

 

VDC within 12 seconds after

 

 

 

 

 

 

EMERGENCY OPERATION switch

 

 

 

is pressed?

 

 

 

 

No

 

 

 

 

 

 

 

 

 

 

 

 

Indoor electronic control P.C. board

CN211

Replace the indoor electronic control P.C. board.

The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.

Measure the voltage between CN211 6(+) and 3(-) while the fan motor is rotating.

 

No

Is it unchanged holding

(Changed)

Replace the indoor electronic control P.C. board.

0 or 15 VDC?

 

Yes (Unchanged)

Replace the indoor fan motor.

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Contents MSZ-FD25VA E1 MSZ-FD25VAS E1 MSZ-FD35VA E1 MSZ-FD35VAS E1 Page Technical Changes Part Names and Functions See control operationSpecifications and rating conditions of main electric parts SpecificationIndoor model Noise Criteria Curves MSZ-FD25VA MSZ-FD25VASWiring Diagram Outlines and DimensionsUnit mm Refrigerant System Diagram Unit mmService Functions Timer Short ModeP.C. Board Modification for Individual Operation J1 J2Auto Restart Function Remote ControllerOperation Microprocessor Control OPERATE/STOPAuto Change Over ··· Auto Mode Operation Cool OperationDRY Operation Heat OperationOutdoor Unit MXZ series Auto Vane OperationHorizontal vane Vertical vane COOL/DRY HeatSee Control Operation Area SettingSee Sensor Daytime Plasma Operation Operation and operating rangeTimer Operation Clean OperationProgram Timer Emergency Operation switch E.O.SW Minute Time Delay OperationEMERGENCY/TEST Operation Troubleshooting Failure Mode Recall Function OFFFlow chart of Plasma operation failure mode recall function Plasma operation checkIndoor unit failure mode table Plasma operation failure mode tableInstruction of Troubleshooting StartTroubleshooting Check Table An abnormality other than above mentioned is detectedPlasma Trouble Criterion of Main Parts Troubleshooting Flow Power lamp flashes 3-time Indoor fan does not operateYes Check of indoor P.C. board and indoor fan motor How to check miswiring and serial signal error Check of installation of the horizontal vane Electromagnetic noise enters into TV sets or radios Indoor electronic control P.C. board Test Point Diagram and VoltageSW P.C. Board CN1 Disassembly Instructions Removing the panel PhotoPower monitor receiver Removing the electrical box Photo Removing the nozzle assembly PhotoRemoving the vertical vane motor unit Photo Removing the horizontal vane motor Photo Removing the indoor fan motor and the line flow fan PhotoSpecifications subject to change without notice