Mitsubishi P240 User Manual

[ 

IX  Troubleshooting ] 

- 229 -

HWE09120

GB

When the remote controller operation SW is turned on, a temporary operation display is indicated, and the display lights out 
immediately.

1)   The power is not supplied to the indoor unit.

ŒThe main power of the indoor unit (AC208/230V) is not on.

ŒThe connector on the indoor unit board has come off.

ŒThe fuse on the indoor unit board has melted.

ŒTransformer failure and disconnected wire of the indoor unit

ŒThe indoor unit board failure

2)   The outdoor control board failure

As the indoor unit does not interact with the outdoor unit, the outdoor unit model cannot be recognized.

YES 

YES 

YES 

YES 

YES 

NO 

NO 

NO 

NO 

NO 

NO 

YES 

*1 

*1 

Check LED1 on the  

indoor unit control board. 

Is it lit? 

When it is lit 

When it is off  
or cannot be checked 

Check for the change of LED  
display by operating dip  
switch SW1 for self-diagnosis. 

Check voltage of the power supply  
terminal on the indoor unit. 

AC208/230V?

Check the fuse on  
the circuit board. 

Melted? 

Check 200V circuit for  
short circuit and ground fault 

Check the connection  
of the connector. 

Check the main power of  

the power supply wire 

Turn on the  
power again. 

Connector contact failure 

Disconnected? 

Check the resistance value  

of the transformer 

Within specification? 

Check the cause of the  
disconnected transformer. 
 Ground fault on the circuit board 
 Ground fault of the sensor and the LEV 

Check self-diagnosis function  

of outdoor unit 

Changed? 

Changed? 

Outdoor unit board failure 

Check self-diagnosis function of  
outdoor unit after the power on. 

Accidental  
error 

Indoor unit control  
board failure 

Correct  
the error. 

*1. Refer to the parts catalog “transformer check”.