17.4.16. J3 Malfunction 
When the voltage signal that IPM send to compressor drive chip is abnormal, the 
display LED will show “J3” and AC will turn off. 
J3 display
J3 display
PFC module protection
PFC module protection
Check whether the 
connecting line between 
main board and the PFC 
module is connected tightly
Check whether the 
connecting line between 
main board and the PFC 
module is connected tightly
Yes
Measure whether the voltage 
between P and N is normal 
refer to the Appendix 3?
Measure whether the voltage 
between P and N is normal 
refer to the Appendix 3?
No
Check  whether  the 
inductance  of  PFC  module 
is good? If the inductance is 
good,  the  resistance  of  the 
two ports is 0
Check  whether  the 
inductance  of  PFC  module 
is good? If the inductance is 
good,  the  resistance  of  the 
two ports is 0
Yes
Replace the inductance
Replace the inductanceNo
Connect it tightly, check 
normal or not
Connect it tightly, check 
normal or not
Replace the outdoor main board
Replace the outdoor main boardYes
Yes
No
No
Replace the PFC module
Replace the PFC module
Trouble is solved
Trouble is solved