Mitsubishi Electronics MSH-A18ND service manual Check of indoor electronic control P.C. board

Page 15

The unit doesn’t operate with the remote controller. Also, the OPERATION INDICATOR lamp doesn’t light up by press- ing the EMERGENCY OPERATION switch.

C Check of indoor electronic control P.C. board

Check the both “parts side” and “pattern side” of indoor electronic control P.C. board visually.

Turn OFF the power supply.

Remove indoor fan motor connector CN211 and

vane motor connector CN151 from the indoor electronic control P.C. board and turn ON the power supply.

Does the unit operate with the remote controller?

No

Does the OPERATION INDICATOR lamp light up by pressing the EMERGENCY OPERATION switch?

 

Yes

 

 

 

 

 

 

 

Turn OFF the

 

Replace the vane

Turn OFF the

power supply.

 

motor.

power supply.

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is winding

 

 

 

 

 

 

 

resistance of

 

 

 

 

 

 

 

 

 

 

 

 

 

vane motor 0 "?

 

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is winding

 

 

 

 

 

 

 

resistance of

 

 

 

 

 

 

 

No

 

 

 

fan motor 0 "?

 

 

 

 

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace the fan

 

 

 

 

 

 

 

motor.

 

 

 

 

 

 

 

 

 

 

 

 

 

Replace the fuse.

Yes

Is fuse(F11) blown? No

Is varistor(NR11) burnt? Yes

Replace the varistor.

Varistor (NR11)

Fuse (F11)

Indoor electronic control P.C. board

No

Replace the indoor

 

electronic control

 

P.C. board.

15

Image 15
Contents Revised EDITION-B ContentsIndoor Unit MSH-A18ND MSH-A24ND AccessoriesTechnical Changes Part Names and FunctionsRemote Controller MSH-A18ND MSH-A24ND MSH-A18ND MSH-A24ND SpecificationMSH-A18ND MSH-A24ND Indoor Unit Outlines and DimensionsWiring Diagram MSH-A18ND Indoor UnitMSH-A24ND Indoor Unit Refrigerant System Diagram MSH-A18ND MSH-A24ND Service FunctionsHow to release Auto Restart Function Take care of the following during servicing TroubleshootingInstruction of troubleshooting Troubleshooting check table Trouble criterion of main parts Check of indoor fan motor Check of indoor electronic control P.C. board How to check mis-wiring Indoor electronic control P.C. board MSH-A18ND MSH-A24ND Indoor Unit Operating Procedure Photos Disassembly InstructionsOperating Procedure Photos Parts List non-RoHS compliant Accessory and Remote Controller AIR Cleaning Filter RoHS Parts List RoHS compliant Vane Motor Vertical AIR Cleaning Filter Page Page Made in Japan