Samsung RM255BABB, RM255BASB manual Diagnostic, For C/R-Fan, For C/F-Fan, For R-Ran, For F-Fan

DIAGNOSTIC

Start

NO

Is the COMP OFF State?

FOR C/R-FAN

Is the voltage DC 0-1V between GND of the main-PCB section and\ CN76 pin No. 5?

NO

Is the voltage DC5V between the main

PCB section CN No.9 and No.14?

YES

			Execute Forced operation.
FOR C/F-FAN	YES
Is the voltage DC 0-1V between GND of the		YES
main-PCB section and CN76 pin No. 2?
	NO
			Fan works normally.
Is the voltage DC5V between the main PCB		NO
section CN No.2 and No.7?
	YES		Troubleshoot the connections
			of door S/W.

			Apply power around 5 minutes	In the first power application, the
	Measure with the closed door.
	- Door Open: DC 0V		after the power OFF. (to prevent	freezer / refrigerator / compressor
	- Door Close : DC 5V		overload of compressor.)	fans work for 5 minutes regardless
				of the condition.
FOR R-RAN		FOR F-FAN

Does DC 0V alternate with DC 12V between	Does DC 0V alternate with DC 12V between	NO
GND of the main-PCB anf cn76pin NO.5?	GND of the main-PCB and CN76 pin No. 2?
YES	YES	Exchange or troubleshoot the
		main PCB.

Reference

CN76 No. 3(C/F-FAN), pin no.6(C/R-FAN) will get pulse signals which is generated when the motor rotates.

These signals will be inputted into MICOM.

Unless signals are not inputted in the motor operation, it will be ON 10 seconds after the fan OFF. But if signals are not still entered, the above operation will be performed four times more. Without signals entered continuously, the motor will get restarted after 10 minutes.

This function is effective to secure normal operation where the motor would be restrained due to foreign matters such as ice. Ref

Expected causes :

1.Fan motor has failure itself.

2.Wire connections have a trouble of contact.

3.Check : Input of the fan motor rotation pulse in operation of fan motor. (See the details of Fan Motor Drive Circuit section.)

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