Samsung LE26B450C4H, Service Manual

Page: 61 / 107

4-2
4. Troubleshooting
4-1-2. No Power
Symptom
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.
The units appears to be dead.
-
-
-
Major
checkpoints
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.
Check the fuses of each part.
Check the output voltage of SMPS.
Replace the Main Board.
-
-
-
-
Diagnostics
Yes
Does proper Main B12VS_PW,
B13V_PW, B5V_PW appear at
TP2007~8, TP2020~2, TP2013~6?
Does proper B3.3V_PW, B1.9V_PW,
B1.25V_PW appear at
C2607, C2590, C2105?
Change the LVDS cable
No
Yes
Does proper PANEL_VCC_PW
appear at LVDS connector Pin #1~5
of T-con b’d?
No
Yes
Lamp(Backlight) Off,
power indicator LED on?
Yes
No
Change the 30P power cable
or IP board
Does proper Stand-By DC
A5V_PW appear at TP2004?
No
Change the Main Assy
Yes
Does proper A3.3V_PW
appear at R2028?
Yes
Does proper DC B12V
appear at F1 of T-con b’d?
No
Yes
Change the T-con b’d
No
No
A power is supplied to set?
No
Check a other function
(No picture part)
Replace a LCD Panel
Caution
Make sure to disconnect the power before working on the IP board.