Haier U Series Service Manual page 75

7.4.3 The IPM and outdoor PCB don't communicate or
Related Abnormality
Communication is detected by checking the IPM module and the outdoor PCB
Troubleshooting
Check whether Terminal CN3 on
the outdoor mainboard CN10 on
IPM module is well inserted.
Electrify the machine again and
turn it on, Check whether the
voltage ofl CN10 is about
DC15V,
Replace the outdoor
mainboard with a new one
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
Be sure to turn off power switch before connect or disconnect connector,
parts damage may be occurred.
No
No
Yes
Pull out and reinsert the terminals.
Yes
Replace the outdoor IPM module
with a new one.
72
or else
Domestic Air Conditioner