Samsung AM14A1E07, Service Manual

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Samsung Electronics
5-11
Troubleshooting
5-2-8 When the SV-B is malfunctioning
1) Checking points
(1) Is the SV-B under normal operating condition?
(2) Is the voltage of the power normal?
(3) Is the SV-B connector (CN75) in good contact?
(4) Is the resistance at both ends of the solenoid about 1.4k
Ω
?
2) Checking pro c e d u re s
N
Y
Y
Y
N
N
Y
N
Y
Y
N
N
N
N
Y
Y
Y
N
Turn off the outdoor power, and then turn it on after 5
seconds
Does the SVA operate when the room B among the indoor
unit room B and room C is turned on?
Does the photo-coupler (IC02) for the room B among the
indoor unit room B and room C operate?
Is the voltage of about DC5V or above applied to
both ends of the C905?
Is the voltage of about DC6V or above applied to
both ends of the C901?
1 Is the 14th pin output of the IC04 maintained at
"High" level?
2 Is the Ist pin output of the IC04 maintained at
"Low" level?
Are the Q906, Q907, and Q909 under turn on condition,
and is the Q908 under "turn off" condition?
Is the Q703 turned. on, indicating the
operating of the SV-B relay (RY73)?
Normal operation
Check and replace the photo coupler (IC02)
•Check and replace the R929, and R930
•Check and replace the C905
•Check and replace the R901, R928 and D908
•Check and replace the C901
1 Is the voltage of the 12th pin
for the IC04 about DC7V?
2 Is the voltage of the 3rd pin
of the IC04 about DC5V?
•Check and
replace the IC04
•Check and
replace the
resistance(R902,
R903,R905,R906)
Check and replace the relevant transistor
Check and replace the D905, D909, and Q703 relay
(Coil resistance at both ends of the relay:about 400
Ω
)
Replace the SV-B solenoid valve