SAMSUNG PS42D51SX bad picture

[Stanislav]

After damage to my TV, I changed this board which was quite damaged


That picture looks, after the change of board

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Wrong board... you need to swap the X-main, not the Y-main when you get those symptoms.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Hi Tom thank you again for the reply

Initially there was no picture, of this picture came after the change of board.

We will now look at other bord, and will order.

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Check the fuse on it, if it has one.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Yes, there I checked it-ОК

The old. Y board has five blown transistors

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Today came the X board ,but with it there is no change in the picture.
remove the power cabel but nothing changes in picture.

If you have any ideas please share them

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Check the Yfr and Yrr settings on the new Y-main. Tweak them gradually and see if the picture improves. Also, check the Vset, Vsc and Ve voltages. In particular a low Ve can sometimes cause this.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Hello Tom

for smooth rotation of the trimmer ,picture is improving but very few.


To check the voltages I need some help

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Have you adjusted Yrr too?
Post a close shot of your power supply (both the main one and the smaller sub-one), I can help you locate the test points.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

I change and Yrr picture changes but not enough.
I checked these values of Volt in the picture -ОК



This is a picture of the entire Board

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

I saw them

[tom66]

Re: SAMSUNG PS42D51SX bad picture

OK, the first step is to adjust the VS, VA voltages so that they are within 1V of the specification. (Ideally +/-0.2V.) The specification is on the back of the plasma panel, the sticker that says NTSC/PAL.

To adjust you need to measure the voltage at the particular test point and

Once you have adjusted those post a picture of the white board adjacent to the power supply -- it has the other voltages on it which are also important for the plasma display to work properly.

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Va and Vs are perfect

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Good. Now check Vscan and Vset. There could also be a Ve voltage, though that might only be present on newer displays.

BTW, did you ever fix the Panasonic P50G20E?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

Vscan ,Vset, Ve are perfect

Panasonic me crazy too ,Work 2-3 days and then goes bad, If you leave after 5 minutes a bad job works that never damaging. sometimes do not want to Tuned ON. I do not know what to do

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Hmm, I cannot think what is causing the issue if all the voltages are good. tieny found that he had a shorted transistor in the Yfr/Yrr area which was causing overdiffusion. You are seeing underdiffusion in this case, but either would be possible. You replaced 5 FETs but maybe that wasn't enough...


I suggested you reflow the Panasonic board, did that have any effect?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

I changed the whole board Y not only transistors.

there's something strange. I leave the TV to work 5 minutes ,coolers of Y board are HOT but coolers of X board are cold (ice) It's probably not normal


What do you mean to reflow the Panasonic board

[tom66]

Re: SAMSUNG PS42D51SX bad picture

See the symptom looks exactly like a failed X board but you said you'd replaced it. Are you 100% sure it is a working board?

[Stanislav]

Re: SAMSUNG PS42D51SX bad picture

NО . I bought it on eBay

[tom66]

Re: SAMSUNG PS42D51SX bad picture

Check the fuse on it (does it have one?)