SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

[Sraros]

Hello,

I got this plasma TV that has a very small crack from side to side let's say 3cm and looks like it's just the outer glass.
As my friend said, the TV was working fine without any distortions, discolor etc on the picture. Now, after a couple of months the TV has no picture, but it has sound.

With a quick MM voltage tests I have
Vs= 8V
Va= 0.2V
VSON at T-con= 0V

Does this mean the panel is dead?

[Sraros]

Re: SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

nothing? nobody?

[Sraros]

Re: SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

Vs upon startup reaches 200V and then rapidly drops to 2-3V.

Disconnected X and Y sus same thing.

Disconnected ribbon of Y to T-con and now Vs is stable.

I found an IGBT shorted: 30F123.

I have some spare IGBTs 30F125 from another board. There is a small difference between them. Can I substitute??????????
Below their datasheets

[Unspun01]

Re: SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

30F125 appears to have higher rating (330V) than the 30F123 (300V). Both have same current rating. I would say that is a suitable substitute.

I have replaced 30F122 (300V/120A) with 30F124 (300V/200A) in the past and was successful in the repair.

Also check the gate drive resistors (low ohm resistors) to make sure they did not fail open during the fault. Also double check the IGBT driver ICs for shorts/faults as a result of the IGBT failing.

Good luck.

[Sraros]

Re: SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

Thanks for the advises. I put the IGBT and the Y-buffer seems ok. I checked the resistors also and they are fine.
When the ribbon to the T-con is unplugged I have stable voltages including Vsc=-178
If I plug the ribbon Y to T-con, with or without the Y-buffer connected my voltages drop rapidly again.

Is this and the little crack on the panel connected? Maybe I am trying without purpose but shouldn't while the Y-buffer is disconnected and the Y/T-con ribbon connected the voltages to be stable?

[Unspun01]

Re: SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

Regarding the crack - it is tough to say.

I have an old 2006/2007 LG plasma TV (42PC3D) with front glass and inner plasma panel laminated together. The front glass is cracked, and even the plasma panel underneath is cracked, but because the two are laminated and sealed together, the panel works ok (except for a small 1" area by the crack).

This is exceptional for a plasma TV because I have never seen a plasma work with a crack before. It may be the only working cracked plasma TV on the planet...lol

It is definitely because the vacuum is still preserved in the plasma panel.

In my TV the front glass crack and the plasma crack are directly overtop of each other and hard to see. You may need to use a magnifying lens to determine if your inner plasma panel is indeed cracked or not.

I have never seen laminated plasma panel undamaged if the front glass is cracked... They share mechanical strength and if one cracks the other is usually cracked also.

But this is a Samsung and may have different design. I have a few cracked Samsung plasmas with laminated outer/inner screens and they definitely do not work.

You will need to look very closely to see if your inner plasma panel is cracked

[Sraros]

Re: SAMSUNG PLASMA TV PS50C430 (S50HW-YB06), no picture with sound

Thx, I ll have a look into it, even if I have already disassembled it for parts