Sony KDL-50W829B not picture, everything else works.

[edless]

Hi,

I have a similar problem to this thread: https://www.badcaps.net/forum/showthread.php?t=67291 but I don't want to hijack / muddy his thread.

The TV is 18 months old and just suddenly stopped showing a picture, no OSD just a backlight which changes brightness depending on what it wants to display. The sound works, channel changing works etc. I've done various diagnostics but the attached photos speak the most words.

The first photo is with either both TCON cables attached, both detached or just the left cable attached. Note the banding at the top and bottom of the left of the screen (exposure is set high to capture it).

The second photo is with just the right TCON cable attached. Here I get a perfect right-hand side of the screen but the left isn't a uniform white, it has that banding issue.

So it seems there is banding on the left side of the panel even when it isn't receiving data. Is the panel scrap or is there something else I can try / check? The thread linked at the top has photos of the setup/layout of the boards as it's the identical model.

Thanks

Ed

[budm]

Re: Sony KDL-50W829B not picture, everything else works.

Look for shorted or very low resistance caps on the tab bonding board.

[edless]

Re: Sony KDL-50W829B not picture, everything else works.

Thanks. Going to take off plenty of screws and have a look.

[edless]

Re: Sony KDL-50W829B not picture, everything else works.

Checked all the caps and the 2 transistors - They're all fine.

Also tried swapping over the 2 TCON cables which made no difference. Can a TCON issue cause problems on just one side of the screen or is it just a faulty panel?

[budm]

Re: Sony KDL-50W829B not picture, everything else works.

Ca we see the 2 Transistors on that tab bonding board?

[edless]

Re: Sony KDL-50W829B not picture, everything else works.

I've already checked them and I've put that area all back together now.

[budm]

Re: Sony KDL-50W829B not picture, everything else works.

I do not expect it to have transistors on the tab bonding board.
Not much you can do at this points if all the caps tested OK and not showing low resistance.

[edless]

Re: Sony KDL-50W829B not picture, everything else works.

I was going to try covering some of the contacts on the TCON cable that does the non working left side but before that I noticed I was getting vertical lines wherever there was text (like channel number, and where it says no signal). I had noticed this earlier on while tinkering about and just thought it was due to lack of shielding while messing about.

I believe I may have inadvertently damaged the TCON. I noticed that one of the tcon cables a couple of contacts had folded over. Upon straightening them out it didn't solve the issue so I wonder whether it may have shorted something. However, I tried putting tape on the faulty side and after a few tries managed to get the faulty side to display for the first time, albeit with vertical lines where text is.

[budwich]

Re: Sony KDL-50W829B not picture, everything else works.

you might try finding a replacement cable. Further, swap the cables from the other side and see if the problem moves... that will likely confirm a bad cable as oppose to a tcon.

make sure you use your glasses when disconnecting / connecting the cable to ensure proper seating... :-)

I see you already tried the swap... :-(

[edless]

Re: Sony KDL-50W829B not picture, everything else works.

It looks like classic a classic TCON issue when I attached the satellite cable, the lines are throughout the whole screen and sometimes I can make out what is on the picture but most of the time I cannot. Moving and re-seating the TCON cables made no difference.

I'll see what happens when the cheap TCON board arrives to feed my curiosity.

[ronhayes]

Re: Sony KDL-50W829B not picture, everything else works.

Hi Ed
Could you let me know where you are getting the cheap t-con from and what do you call cheap ?
The t-con's i have been getting are from spares2repair and have been costing me £30.00 with the postage cost.
There are two types for the KDL-50W829b one is 50T20-C00 and 50T20-C04 what type is yours?
Ron