No Power (X4) - Samsung LA22C450E1 Service Manual

4-1-1. No Power (X4)

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:
Major
Check the internal cable connection status inside the unit.
-
checkpoints
Check the fuses of each part.
-
Check the output voltage of SMPS.
-
Replace the Main Board.
-
Diagnostics
Power indicator LED on?
Yes
Lamp(Backlight) On?
Yes
Does proper Stand-By DC A5V
appear at TP - A5V ?
Yes
Does proper Main DC B13V, B5V
appear at TP - B13V, B5V ?
Yes
Does proper DC A3.3V
appear at TP - A3.3V ?
Yes
Does proper B3.3V, B2.5V, DDR B1.29V
appear at BD430 (B3.3V)
BD418 (B2.5V) BD416 (DDR B1.29V)?
Yes
No
Change 18p power cable.
No
Change the Inverter(Balance B'd).
No
No
Check IC3002 (X4).
Change the Main Assy.
No
No
4. Troubleshooting
4-13