Samsung RS265 LAWP Service Manual page 85

12. Safety Instructions on Service
12-1) Wire connector on the cabinet door.
12-2) How to check relay failure
Note) NC -> Normally Close (C terminal and ON terminal)
NO -> Normally Open (C terminal and Open terminal)
C -> Common Terminal
Div. of contact Voltage at both terminal of coil and trigger Both terminals of contact
DC 12V (Working Condition)
3-contact
terminal
DC 0V (Stop Condition)
Relay
2-contact
DC 12V (load working condition)
terminal
DC 0V (load stop condition)
Relay
DC 12V (load working condition)
SSR
DC 0V (load stop condition)
Disconnect the connector of the main PCB
CN70 and CN71, then check the follows :
1. Measure the voltage at both terminals of a coil and
determine if the relay is working.
2. Measure the voltage at both terminals of a trigger and
determine if SSR is working.
3. Measure the resistance at both terminals of a load
contact, and determine if there is an error in voltages of
coil and trigger.
Resistance value
Between C and NO 0 (Short) -> Normal
Between C and NC (Open) -> Normal
Between C and NO (Open) -> Normal
Between C and NC 0 (Short) -> Normal
Between both termi n al s of contact
0 (Short) -> Normal
Between both termi n al s of contact (Open) -> Normal
Between both termi n al s of contact
About 4-5 (Short) -> Normal
Between both termi n al s of contact
(Open) -> Normal
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