Service Diagnosis
53 
 Domestic Air Conditioner
7.4.3 Indoor AC fan motor malfunction
Indoor Display   
E14
 
 
Method of       
The rotation speed detected by the Hall IC during fan motor operation is used to determine   
Malfunction   
abnormal fan motor operation
 
Detection 
Malfunction   
when the detected rotation feedback singal don’t receiced in 2 minutes
 
Decision     
Conditions 
 
Supposed       
■ Operation halt due to breaking of wire inside the fan motor . 
Causes
         ■ Fan motor overheat protection 
■ Operation halt due to breaking of the fan motor lead wires 
■ Detection error due to faulty indoor unit PCB         
Troubleshooting    
* Caution   
Be sure to turn off power switch before connect or disconnect connector,      or 
else parts damage may be occurred.   
 
 
 
Check whether terminals 
on indoor pcb is well ? 
Electrify the machine again and turn it on in the cooling operation, 
Measure voltage between the    positions 1and 3 of Terminal CN5 on 
the indoor PCB 
the voltage is about 90-220vac   
check whether motor can run 
when turn on the unit 
the indoor motor is damaged and need replace
Yes
NO
NO
Yes
Measure whether there is voltage pulse(0-5VDC) 
between the positions middle wire and black wire 
of Terminal CN2 on the indoor PCB 
NO 
the indoor pcb is damaged and need replace 
 
Pull out the terminals on the indoor 
mainboard and reinsert them. 
No 
Yes 
Is it ok? 
Yes