Troubleshooting By Symptom - Samsung W0690 Service Manual

5-2 Troubleshooting by Symptom

5-2-1 No power
1) Check points
(1) Is the voltage of the power source normal ?
(2) Is the electric wire in good contact ?(CN 71, RY 71)
(3) Is the output voltage of the IC01(KA 7812) normal ?(DC 11.5V ~ DC 12.5V)
(4) Is the output voltage of the IC02(KA 7805) normal ?(DC 4.5V ~ DC 5.5V)
(5) Is the connection of the assembly main PCB, and assembly panel PCB in good contact?(CN91, CN92)
Turn off the power, and then turn it on again five
seconds later.
Dose the buzzer sound, when the power on?
Check whether the "COOL" LED lamp is on, and the
operation starts when pressing the ON/OFF button of
the remocon.
Is the F01(3.15A) fuse blown?
Is the primary voltage of the trans(TN71) normal?
Is the secondary voltage of the trans(TN71) normal?
(AC 13V ~ AC 17V)
Is the rectifying diode(D101~D106) normal?
- Is the voltage of DC 17V ~ DC 23V applied at both
ends of the C102 electrolytic condenser?
- Is the voltage of DC 12V applied at both ends of
the C104 electrolytic condenser?
- Is the voltage of DC 5V applied at both ends of
the C105 electrolytic condenser?
Are the IC01(KA7812) and IC02(KA7805) normal?
Replace the assembly main PCB.
5-2
N
N
N
Y
Y
Y
Y
Y
Y
Normal operation.
Y
Normal operation.
Y
Replace the fuse.
N
Check the power cord and electric wire.
N
Check and replace the trans(TN71).
N
• Check the D101 ~ D106 for cold soldering.
• Replace the diode
• Check both ends of the C102 for short
and cold soldering.
N
• Check the +12V for a short.
• Check the +5V for a short.
• Check and replace the C102, C104,
and C105.
• Check the IC01, and IC02 for cold
N
soldering and a short.
• Replace the IC01, and IC02.
Samsung Electronics