The room is not cooled at all
or not cooled.
The compressor does not operate.
Push the button "AUX." on
the indoor unit, for more than 5 sec.
Using a tester, measure voltage at
the terminals on the terminal board.
Is the voltage
between terminal "N" and
"1" of the terminal board the
power supply voltage ?
Measure resistances of TH1 and TH2.
Are the resistances
conformed Fig. 1 ?
The control circuit is normal.
The compressor may be defective.
The running capacitor may be defective.
Refrigerant may be leaked.
The outdoor fan motor may be defective.
The outdoor fan motor capacitor may be defective.
Fig. 1 Temperature properties of indoor thermistors
No. 3 to 4
No. 1 to 2
To measure the resistance, first remove
the connector as shown at right.
Heat exchange thermistor
25°C resistance 15 K
Replace the PWB ass'y with a new one.
Replace the thermistor ass'y with a new one.
thermistor TH1 (yellow)
25°C resistance 10 K