SHARP(CHINA)INVESTMENT CO.,LTD 
5. Display EC 
Problem symptom  Display EC 
Cause  Outdoor communication fault between power source board and 
intelligent power module 
Malfunction No.  Content of diagnosis  Action 
1  Check the contact of communication wire (CN5) 
between power source board and intelligent power 
module 
Insert again if loose. 
The indicator on power 
source board flare normal 
(bright for 1 second and dark 
for 1 second), but the 
indicator on intelligent power 
module does not work 
normally 
Replace the intelligent power 
module 
If the fault remains unsolved, 
replace the power source board 
again. 
2 After the complete 
unit is energized, 
check the indicators 
on outdoor power 
source  board and 
intelligent power 
module 
The indicator on intelligent 
power module flare normal 
(bright for 1 second and dark 
for 1 second), but the 
indicator on power source 
board does not work normally
Replace the power source 
board 
If the fault remains unsolved, 
replace the intelligent power 
module again. 
You can check each voltage of the electrical board communication pin, the normal data is as the following: 
 
Pin 1 2 3 4 5 6 
Voltage(V) 
5 1.0-4.8 1.8-4.1  2.6 earthing 15 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                
 
 
 
 
 
 
 
 
 
Outdoor communication circuit     
3-13