Read Sharp AE-A24 (serv.man8) Service Manual online
27
AH/AY-AP18DR
AH/AY-AP24DR
AH/AY-AP24DR
TROUBLESHOOTING GUIDE OF CONTROL CIRCUIT
measure the secondary voltage
of transformer.
of transformer.
YES
NO
YES
NO
The machine does not function
at all with remote controller and
switch on the indoor unit.
at all with remote controller and
switch on the indoor unit.
Using a tester, measure the
voltage between anodes of D1
and D2 on PWB ass'y.
voltage between anodes of D1
and D2 on PWB ass'y.
Is the measured value
approx. 17.5 Vac ?
Replace the PWB with a new
one.
one.
Is the WPE1
open circuit ?
Replace the fuse and varistor
with new ones.
with new ones.
Replace the transformer with
a new one.
a new one.
OK
FAIL
Check the cleaning
switch 2(1), CN9, CN8
and lead wires.
Replace the cleaning switch 2(1).
(or reset connector)
(or reset connector)
AH/AY-AP18DR
AH/AY-AP24DR
AH/AY-AP24DR
28
YES
NO
NO
YES
The machine does not function
with remote controller
with remote controller
Push button "O/I" on the
wireless remote controller.
wireless remote controller.
Is transmitting
indicator of the remote
controller active ?
Is indicator lamp of
indoor unit proper ?
Replace the
PWB with a
new one.
PWB with a
new one.
Does beep sound
from the indoor unit ?
Using a tester,
measure the voltage
between terminals
of resistor R26
on the PWB ass'y.
measure the voltage
between terminals
of resistor R26
on the PWB ass'y.
Push the button "O/I".
Are batteries of the
wireless remote controller
proper ?
Replace the batteries
with new ones.
with new ones.
Replace the wireless
remote controller.
remote controller.
When the signal is
received, does the voltage
change ?
Replace the PWB with a new
one.
one.
PWB is normal.
Inspect the outdoor unit.
Inspect the outdoor unit.
NO
YES
NO
YES
Replace the photo
detector unit with a new
one.
detector unit with a new
one.
NO
YES
29
AH/AY-AP18DR
AH/AY-AP24DR
AH/AY-AP24DR
For AY-AP18DR/AE-A18DR, AH-AP18DR/AU-A18DR
The room is not cooled at all
or not cooled.
The compressor does not operate.
or not cooled.
The compressor does not operate.
Measure resistances of TH1 and TH2.
The control circuit is normal.
The compressor may be defective.
The running capacitor may be defective.
Refrigerant may be leaked.
The outdoor fan motor may be defective.
The outdoor fan motor capacitor may be defective.
The compressor may be defective.
The running capacitor may be defective.
Refrigerant may be leaked.
The outdoor fan motor may be defective.
The outdoor fan motor capacitor may be defective.
Push the button "AUX." on
the indoor unit, for more than 5 sec.
the indoor unit, for more than 5 sec.
Is the voltage
between terminal "N" and
"1" of the terminal board the
power supply voltage ?
Are the resistances
conformed Fig. 1 ?
Replace the thermistor ass'y with a new one.
NO
YES
YES
NO
Replace the PWB ass'y with a new one.
Fig. 1
Using a tester, measure voltage at
the terminals on the terminal board.
the terminals on the terminal board.
100
80
60
40
20
0
-10
0
10
20
30
40
Resistance
Thermistor
Room temperature
Heat exchange
Color
Yellow
Orange
To measure the resistance, first remove
the connector as shown at right.
the connector as shown at right.
Room temperature
thermistor TH1
Tester
Connector
No. 3 to 4
No. 1 to 2
Fig. 1 Temperature properties of indoor thermistors
K
Heat exchange thermistor
TH2 (orange)
25
TH2 (orange)
25
°C resistance 15 K
Room temperature
thermistor TH1 (yellow)
25
thermistor TH1 (yellow)
25
°C resistance 10 K
Heat exchange
thermistor TH2
Tester
4
1 CN4
AH/AY-AP18DR
AH/AY-AP24DR
AH/AY-AP24DR
30
For AY-AP24DR/AE-A24DR, AH-AP24DR/AU-A24DR
The room is not cooled at all
or not cooled.
The compressor does not operate.
or not cooled.
The compressor does not operate.
Measure resistances of TH1 and TH2.
The control circuit is normal.
The compressor may be defective.
The running capacitor may be defective.
Refrigerant may be leaked.
The outdoor fan motor may be defective.
The outdoor fan motor capacitor may be defective.
The compressor may be defective.
The running capacitor may be defective.
Refrigerant may be leaked.
The outdoor fan motor may be defective.
The outdoor fan motor capacitor may be defective.
Push the button "AUX." on
the indoor unit, for more than 5 sec.
the indoor unit, for more than 5 sec.
Is the
voltage between
terminal of black lead
wire on the relay in the out door
unit and terminal "N"on the
terminal board the power
supply voltage ?
Are the resistances
conformed Fig. 1 ?
Replace the thermistor ass'y with a new one.
NO
YES
YES
YES
NO
NO
Replace the PWB ass'y with a new one.
Replace the relay in the outdoor unit
with a new one.
with a new one.
Using a tester, measure voltage at
the terminals on the terminal board.
the terminals on the terminal board.
Is the voltage
between terminal "N" and
"4"("2" ..... AU-A24DR) in the outdoor
unit the power
supply voltage ?
