Samsung MC26AC2-07, Service Manual

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Troubleshooting
Samsung Electronics 5-10
5-2-9 When the SV-BY is Malfunctioning (Outdoor Unit)
1) Checklist :
(1) Is the SV1 under normal operating condition?
(2) Is the voltage of the power normal? (the rating voltage ±10% range)
(3) Is the connector (CN76) of the SV-BY in good contact?
(4) Is the resistance at both ends of the solenoid about 1.4k
Ω
?
2) Checking procedures
(1) When either of the indoor units (B & C) is turned on
Turn off the outdoor power, and then turn
on the power in 5 seconds.
Does the SV-BY operate when either of the
indoor units is turned on?
Is the voltage of DC6V applied to both ends
of the C901?
(1) Does the No14 pin output of the IC04
maintain "High"?
(2) Does the No1 pin output of the IC04
maintain "Low"?
Is the No8 pin output of the IC04 in "High"
condition?
Are the Q906, and Q907 in "turn-on" condition?
Is the Q908 in "turn-off" condition?
Does the operation of the Q702 lead to
activation of the SV-BY relay (RY72)?
Replace the SV-BY
Normal
• Check and replace the relevant IC (IC02, IC03).
• Check and replace the resistance (R901, R928, R931),
and diode (D907, D908).
(1) Is the No12 pin voltage
of the IC04 DC7V?
(2) Is the No3 pin voltage
of the IC04 DC5V?
• Check and replace the IC04.
• Check and replace the
resistance
(R902, R903, R905, R906).
Check and replace each transistor
• Check and replace the IC04.
• Check and replace the
resistance (R922, R924).
Check and replace the Q702 and relay.
(Resistance at both ends of the relay: 400
Ω
)
Is the No10 pin voltage
of the IC04 DC7V?
YES
NO
YES
YES
YES
YES
NO
NO NO
NO
NO
NO
NO
YES
YES
YES
YES
DB98_11868A(1)_1 3/3/03 11:17 AM Page 4-8