Haier 2U40S2SM1FA, Service Manual, Page: 48 / 73

Service diagnosis
Domestic air conditioner
Led1 light
NO
YES
Remove fan motor after
switch off the power and restart
the a/c ,the led 1 becomes light
or flash.
Fan motor is
damaged replace it
with a new one.
YES
NO
YES
Test the fan motor terminal resistance
between pin 310V and 0V,or pin15V and 0V
of CN22 are close to 0m with a multimeter
NO
Remove the connection cable
between CN23 of outdoor pcb and
CN10 of module pcb,The led1
becomes light or flash.
YES
YES
The module pcb is
damaged, replace it
with a new one.
The outdoor pcb is
damaged, replace it
with a new one.
NO
Measure the voltage
Between 3 and 4 of IC9 on the
Outdoor mainboard with a Multimete .
The voltage is a constant value of 0V
DC to 5V DC
The outdoor pcb is
damaged, replace
it with a new one.
YES
NO
The outdoor pcb is
well,and then check
the cable
If the voltage is a constant value
of 0V DC to 5V DC.Or the voltage
between Communication line(red ) and N(white
line) is not close to18V
DC when only indoor charged.
YES
The indoor mainboard is
damaged; replace it with a
new one.
NO
Test the outdoor power is
supply 230VAC with a
multimeter when indoor and
outdoor are charged.
LED2 light of the outdoor
NO
The module pcb
is damaged,
replace it with a
new one.
NO
YES
Check the cable
between outdoor
and power
(A)
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