Haier HSU12 - Page 68

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Domestic Air Conditioner
˄A˅
NO
YES
Yes
Check the status of LED1
on the indoor mainboard. If
the LED1 blinks
No
If the voltage is of a
constant value of 0V
DCto5V DC
Yes
measure the voltage between
Jumpers 3 and 4 of IC8 on the indoor
mainboard with a multimeter.
NO
The outdoor mainboard is
damaged; Replace them with a
new one.
If the LED1 is off within two minutes
after the machine is supplied with
power, measure the AC voltage
between positions 1 and 3 on the
terminal of outdoor unit with a
multimeter.
If 230VAC is available bu
t
310DC not, the power module is
damaged, replace it with a ne
w
one.
Test the outdoor power supply
(230VAC and +310VDC) with a
multimeter.
The outdoor mainboard is damaged;
replace it with a new one.
The indoor mainboard is
damaged; replace it with a ne
w
one.
If the value varies between 0 and 80
VAC, the outdoor mainboard is
damaged, replace it with a new one.
If the value is constant at about 30V,
the indoor mainboard is damaged,
replace it with a new one.
If both 230VAC and 310DC
are available, measure
+12V(from7805)is available.
HSU12/18VHJ(DB)
Functions and control
65