Samsung SH18AP0D Service Manual page 27

Troubleshooting
6-2-5 When the Outdoor Unit Does Not Operate. (Initial Diagnosis)
1. Checklist :
1) Is input voltage normal?
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 (CN71) linked correctly?
5) Is the outdoor unit properly connected with the TERMINAL BLOCK connector(N(1), 1, 2, 3)?
2. Troubleshooting procedure
After unplugging out the power cord should be
reconnected within 5 seconds.
Does the OPERATION lamp blink
Does the timer lamp blink during operation ?
Is the power relay RY71 operated by adjusting the
room temperature?
Test rod location
+ -
IC4 Pin No.38 GND
Is rating voltage ±10% range applied relay between
Terminal block No. N(1) and No. 1
26
Yes
Yes
No
#
Normal
Voltage
Condition
RY71 ON DC4.8V
No
Yes
!
Yes
Is the room sensor normal resistor?
10°C
17.96kΩ
No
Check as in the procedure "No Power"
Room temperature sensor is
!
out of order
@
Micom is
No
out of order.
Power relay is
out of order
Outdoor unit is
out of order.
No
@
20°C 30°C
12.09kΩ 8.3kΩ
Yes
#
Sensor Should be
replaced
PCB should be
checked.
Power relay should be
replaced.
Samsung Electronics