SAMSUNG PS42D51SX bad picture

[tom66]

Re: SAMSUNG PS42D51SX bad picture

I am out of ideas now... It is an X-main fault. But it could be the control board not sending the right signals. That doesn't make sense though, because they are generated at the same time as the Y-main. Did you check Ve? +15V & +5V going to X-main?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

I checked them again, Ve -voltage jumps 110-113v

+15v-ok
+5v-ok

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Ve seems OK then, assuming that's what's on the panel, most TV it is around 130~150V though, so do please check it or see if increasing it improves discharge quality.

Ve is used to initialise the discharge of the panel.

Also, please check if when switching on your TV it takes a while for all pixels to become ready (like liquid filling in), or is this effect instantaneous with all pixels working just purple/dim.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

when switching On or change channels ,Pixelс gradually filled

[tom66]

Re: SAMSUNG PS42D51SX bad picture

OK, what does the panel sticker say for Ve then?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Ve-110V

I changed the voltage from 110 to 150 volts, no improvement

[tom66]

Re: SAMSUNG PS42D51SX bad picture

I am now officially stumped. Inspect the flat flex cable for tears or breaks.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

I checked each wire-OK

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Even the ones going to the plasma panel?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

not just the flat cable between the board and management board

[tom66]

Re: SAMSUNG PS42D51SX bad picture

That is one thing I forgot to ask. How is the XS and XG testpoints near there?
I am expecting occasional square wave bursts on XS and XG.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Tom I saw something of the managing board,flashing green LED ,there are four such

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Flashing green LED means the board is working.

Other LEDs indicate plasma panel temperature in binary or on 1-4 scale. All lit is bad. Anything otherwise is OK.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Tom there is not no signal
the first is XS second is XG

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture


since no signal can you check something or again replace board

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Hmm, you should definitely be seeing something on XG, but you are not. Since you replaced the X-main board I would suspect the control board or the cable going to it... try reversing the cable (so that control board side is connected to x-main side, x-main side to control board side) and see if the symptoms change.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

XS bord

XG bord

[tom66]

Re: SAMSUNG PS42D51SX bad picture

BTW, what scale is that on at the moment? 5V/div?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

yes 5vDIV / 2 mikro sek.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

this is the bord