Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

[VividElectrode]

Samsung LN40B500P3FXZA
TCON Board # FHD60C4LV1.1 (hi-res photo attached)

This set is showing what i would call a "gray screen". You can see the picture on the display, but it looks as though gray or white has been overlaid over the entire screen. Photo attached. From doing some reading on this forum, and others, I think I'm safe with the assumption that this is an issue of some sort with the T-con board, but please correct me if I'm wrong.

I'm hoping to find some help tracking down which part of the Tcon board has failed, and hopefully repair it. Yes, I can buy a replacement Tcon on ebay right now for $16 with free shipping. But I'd rather get a little dirty first, if for no other reason than just for a learning experience

The surface mount fuse on the tcon tests good. I haven't measured any voltages on the tcon yet because 1) I'm not sure what they should actually be in order to compare them, and 2) I'm not sure which ones are even relevant to this issue.

From a similar thread, the Gamma IC was called out to be the culprit. You can't read the #s on it in the picture so for reference the gamma IC on this board (ICG1) is Maxim part # MAX9591.

Any help is greatly appreciated, thank you all for your time!

[tom66]

Re: Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

The slightly dim bar that's off centre indicates this is more likely a panel problem than anything else - possibly water damage. It will probably not be repairable, but you can see how bad the damage is. One test, try removing one of the left and right hand ribbons exiting the T-con, see how the picture is with just one ribbon installed.

[VividElectrode]

Re: Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

Here are pictures of what I get when i test with one ribbon plugged in at a time. What should I be learning from this test?

[tom66]

Re: Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

It doesn't indicate much either way. You will have to remove the frame of the panel to expose the tab bonds directly and check for water damage or burn marks.

[VividElectrode]

Re: Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

Ok. So essentially I should just assume this to be non-repairable? Or is it occasionally possible to fix that kind of issue? I will go ahead and pull apart the panel and see what I can find. Also, would the water damage or whatever is causing the "dim bar" also be causing the whole screen to have the gray tint? Or does that appear to be a separate issue?

[tom66]

Re: Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

Ok. So essentially I should just assume this to be non-repairable? Or is it occasionally possible to fix that kind of issue? I will go ahead and pull apart the panel and see what I can find. Also, would the water damage or whatever is causing the "dim bar" also be causing the whole screen to have the gray tint? Or does that appear to be a separate issue?

The water damage is causing both, if there is any. I have seen this before, one tab driver will be damaged and it will pull down the rest of the panel signals.

It's a toss up as to whether it can be repaired or not, but in most cases it can't be because the water eats through the fine PCB and flat flex traces.

[VividElectrode]

Re: Samsung LN40B500P3FXZA Grey/White/Cloudy Screen

Thanks! I will tear into it and see what I can find. Sounds like I'll be salvaging parts!