No Power - Samsung LA37C630 Series Service Manual

4. Troubleshooting

4-1-1. No Power

The LEDs on the front panel do not work when connecting the power cord.
-
The SMPS relay does not work when connecting the power cord.
-
Symptom
The units appears to be dead.
-
The IP relay or the LEDs on the front panel does not work when connecting the power cord if the cables are
improperly connected or the Main Board or SMPS is not functioning. In this case, check the following:
Check the internal cable connection status inside the unit.
-
Major
Check the fuses of each part.
-
checkpoints
Check the output voltage of SMPS.
-
Replace the Main Board.
-
1
Diagnostics
2
3
Make sure to disconnect the power before working on the IP board.
Caution
4-2
LAMP off, power indicator
LED red color?
Yes
Does proper DC 13V appear at
pin21,22 of CN801?
Yes
Does proper DC A3.3V appear at
C1131_NACH, C1132_NACH?
Yes
Does proper DC 5V, 3.3V,
1.25V(B1.2VD), 1.5V, 1.8V(MT_DDRV)
appear at C1140, C1169,
C1163, C1167, C1174?
Yes
A power is supplied to set?
No
Check a connection a power cable.
No
Change a Assy PCB Power.
No
Check a IC1103_NACH.
Change a main PCB ass'y
Check a IC1108, IC1107, IC1109
No
Change a main PCB ass'y
Check a other function.
No
(No picture part)
Replace a lcd panel.