PN43D450A2DXZA has no Video

[RFurball]

I have a Samsung PN43D450A2DXZA TV which has no video output. Audio works fine. Reading a similar post on this forum https://www.badcaps.net/forum/showthread.php?t=37000 it seems the X and Y main boards are likely the culprits.

I opened the TV and first measured the Vs and Va voltages. They briefly came up to their correct values then decayed to 0V. Next I removed both the X-main and Y-main boards and measured for shorts across all transistors. I did not find any shorts.

I next took a gamble and bought an X-main and a Y-main board on eBay. Alas putting these boards in did not fix the problem. Either one of these boards are also bad or it is another problem. I suppose it could be the Y buffer boards. I do not want to dump a whole lot more money into this TV but if there are any other quick checks I can try I would be appreciative.

[tom66]

Re: PN43D450A2DXZA has no Video

No cracks on the panel, even on the edge?

Try checking the Y-buffer:
https://www.youtube.com/watch?v=51SZ...Y&noredirect=1

[Shinju]

Re: PN43D450A2DXZA has no Video

The SMPS will not power on with both x and y out of circuit, how I tested mine to find the xmain was at fault was to pull the power plug to the x board keeping all other boards in circuit and the panel powered up (no picture of course) but I was able to check voltages on the y-main and SMPS as well.

Also once you get this up and running update the firmware ASAP they have a fix for these generation of PDP displays to prevent future failures.

Chances are you got bad parts and like tom66 has suggested test your buffers and look for cracks.

[RFurball]

Re: PN43D450A2DXZA has no Video

Thanks for the replies I will check the Y buffer board as mentioned. That looks like a fairly simple task. There is one small hole in the screen but no cracks. It looks like a the type of hole you get on your windshield when a small rock hits it. Can that be the cause of the short?

[tvsteve2]

Re: PN43D450A2DXZA has no Video

Yes these Samsungs have no protective glass infront of the display like an LG has making it fragile and the damage may have vented the display

[Shinju]

Re: PN43D450A2DXZA has no Video

Can you post a photo of said hole?

[tom66]

Re: PN43D450A2DXZA has no Video

Thanks for the replies I will check the Y buffer board as mentioned. That looks like a fairly simple task. There is one small hole in the screen but no cracks. It looks like a the type of hole you get on your windshield when a small rock hits it. Can that be the cause of the short?

This kills the panel.

It's a known defect with the glass. It's usually not impact damage but thermal expansion. Software update may correct driver algorithm to fix this. The fact that Samsung did not recall the D-series for cracking panels shows how much the company stands behind its products.

[RFurball]

Re: PN43D450A2DXZA has no Video

I added a picture of the crack. Sorry for the quality but cell phone cameras are pretty lame, but it shows the hole with cracks propagating out from it. The cracks are about 0.5 - 0.75 inches long.. It is bigger than I thought, it must of the cracks must have propagated as I moved the TV from my vacation house.

I will still check the boards for shorts since I have an identical model of this television and can use the boards if they fail. I will toss the chassis and screen.

[tom66]

Re: PN43D450A2DXZA has no Video

Yeah, sorry, that's a fatal fault there.