LG 50PC3D Screen Problem "Picture Included"!

[Treydogg77]

Okay so I replaced the Y-sus main, and found 3fets shorted on the lower buffer. Replaced those and hooked everything back up and now I have a color vertical bar that moves across the screen left to right. Any ideas to what's causing this single bar?

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

Okay I hooked a componet signal to it, and now I've got this image. Could this be a ribbon cable not seated properly on a buffer board?

[tw2005]

Re: LG 50PC3D Screen Problem "Picture Included"!

Okay so I replaced the Y-sus main, and found 3fets shorted on the lower buffer. Replaced those and hooked everything back up and now I have a color vertical bar that moves across the screen left to right. Any ideas to what's causing this single bar?

Looking suspiciously like the "NO SIGNAL" which is yellow and randomly dances around the screen and often it's a bad buffer.

I believe buffers have SMD FETs which fail or go short, check them out, could be

[tw2005]

Re: LG 50PC3D Screen Problem "Picture Included"!

just re read and you replaced some, is the lower and upper buffer boards connected to each other?

[tw2005]

Re: LG 50PC3D Screen Problem "Picture Included"!

Is the upper buffer ok?

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

The buffers are connected together. The I replaced all the fets on the lower buffer. The upper buffer tested okay....

[freakaftr8]

Re: LG 50PC3D Screen Problem "Picture Included"!

Something is still amiss with the fets on the buffers. You getting the same reading on all the MOSFETs of both buffer boards?

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

I will remove the buffers and check the fet readings.

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

Okay I checked all the fets on the upper and lower buffer. With my meter in diode test mode this is what I got.

Upper Buffer Fets Reading

Q1 249
Q2 247
Q3 249

Lower Buffer Fets reading

Q103 242
Q102 241
Q101 241

None of them come back shorted. What do I try now guys, could the Y-Sus board cause this problem.

[Alastair E]

Re: LG 50PC3D Screen Problem "Picture Included"!

looks like one is leaky--I would expect a much higher reading--around 700 odd (body-diode) if they were OK.
--those mosfets are wired in parallel...

Replace 'em all with new I would.

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

Okay I will replace all the fets and report my results!

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

Okay I replaced the Fets, and nothing really changed. So I ordered and tested the new buffers before I installed them. Nothing changed, so I ordered a Y-Sus board, and now the screen is white, and you can see a flicker of images moving in the background. I'm bout to right this off as a bad panel! What do you all think?

[Alastair E]

Re: LG 50PC3D Screen Problem "Picture Included"!

Nah--Doubt its the panel.

Check all the various voltages,--but I suspect you bought a dodgy Y-sus board...

[ljintexas]

Re: LG 50PC3D Screen Problem "Picture Included"!

I have boards for this set..but I suspect Y-sus has some bad components on it that were damaged by shorted U and L buffers. My set had same malady with moving vertical stripe..I had one of the ribbons to the buffers crack..so panel was toast.

[ljintexas]

Re: LG 50PC3D Screen Problem "Picture Included"!

Alastair thinks whatever is wrong with Y-sus is minor...sounds like yours may have the same malady..

[Treydogg77]

Re: LG 50PC3D Screen Problem "Picture Included"!

Okay gentleman, I think think its time to retire this ole gal! She's been a good one, but I don't see putting anymore $$$ into it. I would like to thank everybody for info and suggestions!