Samsung AC052MN4DKH Service Manual page 64

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Yes
Check the communication circuit of the Main
PCB of the outdoor unit.
1. Is there a fault in communication IC?
2. Is there a fault in TVS-Diode?
Measuring Communication IC Measuring Part
Part (Circuit Diagram)
Location
Measuring #5-GND, #6- Communication A, #7-
Point Communication B, #8-Vcc
Communication IC Measuring (Port)
#6 - #5
#7 - #5
#8 - #5
TVS-Diode Measuring
Both ends of diode
Samsung Electronics
Example of Measuring
Communication IC
CommB(#7)
Steady-state Measuring Value
COM 1(RED)
0.9kΩ ~ 1.2kΩ
0.9kΩ ~ 1.2kΩ
4.7Vdc ~ 5.3Vdc
Steady-state Measuring Value
1kΩ or above
(cont.)
Example of Measuring
CommA(#6)
Remark
Measuring after separating the communicatio
connection
Troubleshooting
TVS-Diode
4-29