PL51D550C1G Plasma Samsung - No picture, but sound is ok

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

The new transistor you have just replaced does it still test ok? try testing like you did before (1-2, 2-3, 1-3)

Sorry, now I understand what you mean. After I turned on the TV a lot of times, I have tested the transistor again and it is ok, no shorts, but still no picture.
So I can say that the problem isn't the panel? Because the transistor didn't blow up again.

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

The new transistor you have just replaced does it still test ok? try testing like you did before (1-2, 2-3, 1-3)

Yes, I did test before replace the old one and it is ok. But still no picture

[vinceroger69]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

The new transistor you have just replaced does it still test ok? try testing like you did before (1-2, 2-3, 1-3)

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

There is a small possibility that could cause the fault.

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Without an oscilloscope, unfortunately not.

(The oscilloscope would verify the Y-main and X-main work. If these boards work, it would indicate the panel is bad)

A cheaper option may be worth trying: the control board. It's rare, but it can fail where the light blinks, but there is no picture.

tom66, just a last question: Do you think that a fail in control board could cause the "explosion" that I heard when picture was gone and that transistor on Y-main to get shorted?

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

That can be one of the ways a panel fails but in that case you would have a subtle glow from the screen but no image on it.

Understood.

I will try to figure out what I'm gonna do with my TV. Maybe I will take it to another tech in my city and see what he is gonna say about it, or maybe I will try to contact Samsung's assistance in a city 350km from here
Anyway, thanks a lot for helping.

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

That can be one of the ways a panel fails but in that case you would have a subtle glow from the screen but no image on it.

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Without an oscilloscope, unfortunately not.

(The oscilloscope would verify the Y-main and X-main work. If these boards work, it would indicate the panel is bad)

A cheaper option may be worth trying: the control board. It's rare, but it can fail where the light blinks, but there is no picture.

I read in some samsung's bulletin that if the fuse on E-buffer board is not blown then the panel is ok. Is that correct?

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Without an oscilloscope, unfortunately not.

(The oscilloscope would verify the Y-main and X-main work. If these boards work, it would indicate the panel is bad)

A cheaper option may be worth trying: the control board. It's rare, but it can fail where the light blinks, but there is no picture.

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

I did replace the transistor... no success, still no picture. At least the transistor didn't blow up.

I think I have to replace both Y-main and X-main boards like the tech said. But I'm afraid to buy those boards and the problem be the panel. Is there really no way to test the panel?

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

The transistor has arrived, I will test today.
Is it worth to replace the transistor and before to turn on the whole set, unplug the panel, then unplug x-main in order to see what is the problem if the transistor blow up again?

I'm about to replace the shorted transistor right now. Should I do these steps mentioned above?

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

The transistor has arrived, I will test today.
Is it worth to replace the transistor and before to turn on the whole set, unplug the panel, then unplug x-main in order to see what is the problem if the transistor blow up again?

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

1 and 2 are the other way around.
Pins are read anticlockwise from pin 1.

Try replacing the FET/transistor, and let us know how it goes.

Sure. I don't think that this transistor is available at eletronics shops in my city, so I will buy in a website that is kind of a "Brazilian ebay".
Thanks a lot for helping. I let you know if it will work.

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

1 and 2 are the other way around.
Pins are read anticlockwise from pin 1.

Try replacing the FET/transistor, and let us know how it goes.

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Ok, I'd check U5012 for shorts between pins 3-4, 4-5 and 3-5. That is the most at risk part.

I just tested it, no shorts.

I assumed that these pins are the pins below, right? Like this:

1__ 2

3 4 5

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Ok, I'd check U5012 for shorts between pins 3-4, 4-5 and 3-5. That is the most at risk part.

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Q5018, is that just a mark on it, or is that burnt?

It is just a mark, I only noticed when I took the picture. I think I quickly touched the IC (with the iron) when I was trying to take off the transistor, because it was very difficult to do it. :S

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Q5018, is that just a mark on it, or is that burnt?

[rogerazambuja]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Sure... Unfortunatelly, I think I quickly touched the iron on IC Q5028. Hope it didn't fry .

[tom66]

Re: PL51D550C1G Plasma Samsung - No picture, but sound is ok

Can you post a picture of the circuit underneath that transistor? It is worth checking the driver components are OK too.