Service Diagnosis
41
10.4.7
The communication fault between IPM and outdoor PCB
Outdoor display:
F3 LED1 flash 4 times
Communication is detected by checking the IPM module and the outdoor PCB
■ The outdoor PCB broken leads to communication fault
■ The IPM module broken leads to communication fault
■ The outdoor PCB is broken
■ The IPM module is broken
■
Communication wiring disconnected
* Caution: Be sure to turn off power switch before connect or disconnect connector,
or else parts damage may be occurred.
Method of
Malfunction
Detection
Trouble
shooting
Supposed
Causes
Malfunction
Decision
Conditions
Are they good?
Pull out and reinsert the terminals.
Replace connected wire
Replace the outdoor PCB with a new
one
Replace the outdoor IPM
module with a new one.
Check whether the CN23 and CN24
terminals of the outdoor PCB and the
CN10 and CN11 terminals of the IPM
module are tightly connected.
Check whether the connection between
the power module and the outdoor P&N
line is tight
Electrify the machine again and turn it on.
Check whether the voltage between 1 and 2
of Terminal CN23 is about DC5V.
Check whether the voltage between2 and 3
of terminal CN23 is about DC15V.
NO
YES
Malfunction unsolved
NO
1 2 3
