Samsung RM255BABB Training Manual page 72

DIAGNOSTIC
6-10) If Water Drawer doesn't work normally
Preliminary Check
1. Stop water supply before disassembling or assembling because water is directly supplied to the water valve.
2. Keep in mind to avoid shock hazard during disassembly because power is always present on one side of wire.
Check water coming out when
pressing water lever at
dispenser.
Measure both terminals of RY7C
contact point after disconnecting
CN72 and CN73 connectors.
Start
Does it work normally when
selecting water?
NO
Was dispenser water
s/w pressed?
NO
Does Main MICOM No. 13 maintain
0V when pressing water s/w?
YES
Does IC74 No. 16 maintain 0V
when pressing water s/w?
YES
Is RY70 relay AC contact terminal
0Ω when pressing water s/w?
YES
Normal Main PCB
- Need to check other sections.
Check the wire between WATER
SOLENOID VALVE and MAIN PCB.
Failure of WATER VALVE itself connector
contact failure
Check for connecting pipe failure.
74
71 71
YES
Normal Working Condition
YES
Check the instrumental interference
of dispenser water s/w.
NO
Check CN50 connector, wire
and failure of water s/w itself.
NO
Main PCB failure: Replace it
(IC74 failure).
NO
Main PCB failure: Replace it.
(RY7D Relay Contact Terminal
Short Failure)