Daewoo DPN-4274NHS Service Manual - page 40

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[NOTE] Refer to “PDP MODULE” section for trouble diagnosis other than MAIN, SUB and POWER

PCB.

1. Common checking process when “No signal” or “No raster”

(No signal: OSD is working but no images are displaying, No raster: Not even OSD is displaying)

2. When “No signal” in Video, S-VIDEO, and Component modes.

(1) First check if PC input is working.

If PC is not working replace MAIN PCB.

For detail examination, with an oscilloscope check TP188, TP184 and TP187 signal explained

in A/V block section.

If TP188, TP184 or TP187 signal does not appear, replace MAIN PCB.

(2) Checking waveforms with COLOR BAR pattern(for detail examination only)

8. Main PCB Trouble Diagnosis

  Does "No si gn al " screen

appear ?

Is the signal input Jack

properly connected?

Does input source (AV

device) work ?

Is a weak

discharge detected

 in the screen?

1.Check AC connection

2. Check Power S/W ON

3. Check other PCBs

N

N

N

Check the connectio n of

Jack(PDP and AV device)

Is LVDS connecti on

 correctly connected?

Check LVDS connection

Is waveform of DVS,DHS,

DCLK in the Main PCB normal?

1. Check other PCBs and connectors

Check AV device

Check input

mode

Ch eck start

N

N

N

N

N

Y

Y

Y

Y

Y

Y

Y

Is input selection in the

Correct mode ?

Y

Replace Main PCB

and/or Sub PCB

CN101 of Digital PCB &

P100 of Main PCB

Replace Main PCB

and/or Sub PCB

TP(187,184,181)

(Refer to PDP Module section)

8-1. MAIN & SUB PCB Trouble Diagnosis