Samsung AQT24A5RE/B Service Manual page 27

Troubleshooting
5-2-3 When the Outdoor Unit Does Not Operate. (Initial Diagnosis)
1) Checklist :
(1) Is input voltage normal? (the rating voltage ±10% range)
(2) Is the set temperature of the remote control higher than room temperature in COOL mode?
(3) Is the set temperature of the remote control lower than room temperature in HEAT mode?
(4) Is the POWER IN connector (CN78) linked correctly?
(5) Is the outdoor unit properly connected with the TERMINAL BLOCK connector(7P)?
2) Troubleshooting procedure
After unplugging out the power cord should be recon-
nected within five seconds.
Does the operating lamp blink
Does the timer lamp blink during operation ?
Is the power relay RY71 operated by adjusting the room
temperature?
Test rod location
+ -
IC06 Pin #40 GND
Is the rating voltage ±10% range applied relay between
5-4
YES
NO
Normal
Condition Voltage
RY71 ON DC 4.8V
NO
CN78 ! and # .
YES
Is the room sensor normal register?
10°C
17.96k Ω
NO
Check as in the procedure "No Power parts"
YES
PCB and Room tempera-
ture sensor should be
checked.
!
!
NO
#
NO
Power relay is
out of order
@
!
NO
(25°C 10KΩ)
20°C 30°C
12.09kΩ 8.3kΩ
YES
#
Refer to page 5-2.
Room temperature sensor is
out of order
@
PCB is
out of order.
Refer to replace
PCB module
Power relay should be
replaced.
Outdoor unit is
out of order.
Samsung Electronics