Haier HSU12VHJ(DB), Service Manual

Page: 63 / 115

Domestic Air Conditioner
tester)
Normal resistance
Several k
Ÿ
to several M
Ÿ
(
и
)
Unacceptable resistance Short (0 Ÿ ) or open
7.3.4 The IPM and outdoor PCB don’t communicate or Related Abnormality
outdoor display LED1 flash 4 times Indoor Display F3
Method of Communication is detected by checking the IPM module and the outdoor PCB
Malfunction
Detection
Malfunction
Ƶ
The outdoor PCB broken leads to communication fault
Decision
Ƶ
The IPM module broken leads to communication fault
Conditions
Supposed
Ƶ
The outdoor PCB is broken
Causes
Ƶ
The IPM module is broken
Ƶ
Communication wiring disconnected
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector, or
else parts damage may be occurred.
NO
NO
YES
Are they good?
1) Pull out and reinsert the terminals.
2) Replace connected wire
1) Check whether Terminal CN23 and CN22 on the outdoor
mainboard CN10 and CN11 on IPM module
2) Check whether the connected wire between IPM and outdoor
YES
Replace the outdoor IPM
module with a new one.
Replace the outdoor mainboard with a new one
Electrify the machine again and
turn it on, Check whether the
voltage between 1 and 2 of
Terminal CN22is about DC5V,
Check whether the voltage
between2 and 3 of Terminal CN22
is about DC15V,
NO
HSU12/18VHJ(DB) Functions and control
60