Haier 2U14CS4ERA, Service Manual

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. .7 The communication fault between IPM and outdoor PCB
Outdoor display: 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
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The outdoor PCB is broken
■
The IPM module is broken
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Communication wiring disconnected
* Caution Be sure to turn off power switch before connect or disconnect connector, or
else parts damage may be occurred.
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 the voltage between2
and 3 of Terminal CN23 is about DC15V,
Replace the outdoor mainboard with a new one
Replace the outdoor IPM module
with a new one.
YES
NO
NO
YES
Malfunction unsolved
1) Pull out and reinsert the terminals.
2) Replace connected wire
Service diagnosis
Domestic air conditioner
Conditions
Supposed
Causes
Troubleshooting
Method of
malfunction detection
Malfunction detection
conditions