Service diagnosis
31                   Domestic air conditioner 
10.3.3 Indoor DC fan motor malfunction 
Indoor Display   
ƵƶƾE14
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 signal don’t received in 2 minutes
Decision     
Conditions 
Supposed        
Ŷ Operation halt due to breaking of wire inside the fan motor. 
Causes
  Ŷ Fan motor overheat protection 
Ŷ Operation halt due to breaking of the fan motor lead wires 
Ŷ 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
12
12
<HV
Measure whether there is voltage pulse (0-5VDC) 
between the positions middle wire and black wire 
of Terminal CN2 on the indoor PCB 
12
the indoor pcb is damaged and need replace 
Pull out the terminals on the indoor 
mainboard and reinsert them. 
1R
<HV
Is it ok?   
<HV