Samsung PN43E450A1F two seconds to black

[tibimakai]

I have picked up this plasma TV, which turns on, I can hear the Samsung chime, there is a second or two a "staticky" image and then the screen becomes black.
Usually I don't pick up plasma TVs and I don't know how to repair them.
I have worked on some plasma TV in the beginning, but those were old model TVs and the only repair I had to do, is replace the Y boards.
Standby 5.3V, 15V is there, PS_On is there for a second and then drops to 0.111V.
There are other voltages that I have measured, but I did not wrote them down yet. One of them it was 10.88V.
It seems like all the voltages are there, except the PS_On.
It could be a mainboard problem, or the PS_On drops because another fault is somewhere else?
Tomorrow, I will take some measurements and I will take some pictures.

[tom66]

Re: Samsung PN43E450A1F two seconds to black

You probably won't want to hear this but this model is prone to micro cracks on the edge of the panel causing this exact symptom. It is a shorted buffer board shutting down the control board/Y-main.

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

Oh noooooooooooooo!!!!!!! Just kidding.
This is how plasmas welcome me? Nice start.
How can I be sure?

[tom66]

Re: Samsung PN43E450A1F two seconds to black

Check the panel for cracks/chips all around. They can look like little scratch marks.

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

I have found your PDP test. Should I do it, or it's almost sure it's the panel?

[tom66]

Re: Samsung PN43E450A1F two seconds to black

If there are no cracks it might not be the panel. You can do the test and see what the results are. On the logic board, does the LED blink about once a second, or once every 5 seconds?

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

5 seconds.

[tom66]

Re: Samsung PN43E450A1F two seconds to black

OK, pull the buffer board (left hand side of panel, looking from the rear of the TV, connects to orange ribbons) and test it as such:
https://www.youtube.com/watch?v=51SZ...Y&noredirect=1

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

Tom, I'm doing this PDP test, but what exactly should happen?

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

I have found at the bottom connector a couple of shorts. They were the last couple of pins.
So most likely the bottom buffer IC is shorted, am I right?

[tom66]

Re: Samsung PN43E450A1F two seconds to black

Yep, so now check that part of the panel for cracks.

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

I already ordered another Y buffer.
Did you see this cracked panels very often?
If the Y buffer board fails, the half Y board(I don't know how it's called the board on the other side) fails too, or not every time.
I'm asking, because I haven't checked that board yet.

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

Found a pretty big crack, after I have removed the front bezel.
So parting out this one, or selling boards which are super cheap for this TV. I paid $40 for it, so it's not a major problem.
Thank you Tom for your help. I will stick to LCD TVs, from now on.

[tom66]

Re: Samsung PN43E450A1F two seconds to black

Plasmas are well worth fixing, but you have to know what to avoid. Just like you avoid Samsung D-series LED-LCD for bad panels, avoid Samsung plasma with 2 secs to black issue.

[tibimakai]

Re: Samsung PN43E450A1F two seconds to black

The Y buffer board came in.
I'm trying first to sell the TV for parts, since the panel is cracked. Boards separately are to cheap.
It is safe to install the new buffer board and turn on the TV, with the cracked panel? It won't blow the buffer board?

[tom66]

Re: Samsung PN43E450A1F two seconds to black

No, it will blow the buffer board. Almost immediately.

If the crack doesn't extend beyond the first panel ribbon, you can fire it up with that ribbon out. You may be able to get it to work with bottom inch missing.

Also, you must test the board you received before installation as most sellers do not.