The Communication Fault Between Ipm And Outdoor Pcb - Haier HSU-18HEA03/R2(DB)-I Service Manual

7.3.5 The communication fault between IPM and outdoor PCB

outdoor display LED1 flash 4 times
Method of Communication is detected by checking the IPM module and the outdoor PCB
Malfunction
Detection
Malfunction
Decision The IPM module broken leads to communication fault
Conditions
Supposed
Causes
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector,
1) Check whether Terminal CN23 and CN24 on the
outdoor mainboard CN10 and CN11 on IPM module
2) Check whether the connected wire between IPM and
outdoor
Are they good?
Electrify the machine again and
turn it on, Check whether the
voltage between 1 and 2 of
Terminal CN23 is about DC5V,
Check whether
between2 and 3 of Terminal
CN23 is about DC15V,
Replace the outdoor mainboard with a new
one
HSU-18HEA03/R2(DB)-I
The outdoor PCB broken leads to communication fault
The outdoor PCB is broken
The IPM module is broken
Communication wiring disconnected
else parts damage may be occurred.
YES
the voltage
NO
NO
1) Pull out and reinsert the terminals.
2) Replace connected wire
YES
64
Service Diagnosis
Replace the outdoor IPM
module with a new one.
Domestic air conditioner
or