No Power (Sx1) - Samsung LA22C450E1 Service Manual

4. Troubleshooting

4-1-1. No Power (SX1)

The LEDs on the front panel do not work when connecting the power cord.
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Symptom The SMPS relay does not work when connecting the power cord.
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The units appears to be dead.
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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.
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Major
Check the fuses of each part.
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checkpoints
Check the output voltage of SMPS.
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Replace the Main Board.
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Diagnostics
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 DC5V appear at
pin 4 of CN210_18P?
Yes
Does proper DC A3.3V
appear at BD215?
Yes
Does proper DC 3.3V, 1.1V
appear at BD216, BD233?
Yes
A power is supplied to set?
No
Check a connection a power cable.
No
Change a Assy PCB Power.
No
Check a IC201.
Change a main PCB ass'y.
Check a IC203, IC204.
No
Change a main PCB ass'y.