Sony KDL-37L4000

[kevinm34232]

Hi someone called me with this TV, picture looks like contrast is turned way up similar to a Toshiba I had with wrong main board. Nothing has been worked on with this TV as of yet. Just curious if anyone has any experience with Sony's and this problem?

[kevinm34232]

Re: Sony KDL-37L4000

I reflowed the main board in the oven, cleaned the LVDS connections, and there was no change. Im thinking it is a bad main board, can a t-con cause this issue though?

[drpj23]

Re: Sony KDL-37L4000

What does the OSD look like? I have a M4000 with pic issues (image just has whites/yellows/reds/ and black), I am thinking this is a main too.

[kevinm34232]

Re: Sony KDL-37L4000

OSD looks OK but still not right, it's just not as noticeable. The color is off. I tried a factory reset and got into the factory menu but nothing has helped.

[tom66]

Re: Sony KDL-37L4000

I'm thinking T-con personally though I wouldn't rule out the main board.

[kevinm34232]

Re: Sony KDL-37L4000

Hmm Tom remember the Toshiba I got hat had the wrong main board put in for a different model panel? This is very similar to what it looks like, that's why I was thinking main board.. The parts are expensive and pretty rare I guess Ill try to see if I can find both and try each one..

[kevinm34232]

Re: Sony KDL-37L4000

Well I got new main board today but same problem. So I put old main board in and started looking at t-con (AUO 5537T03C02).
I froze the t-con board and plugged it in, and although most of the IC's defrosted pretty quickly, the one that went first was the one labeled AS15-U which closest datasheet I found was
https://cdn.badcaps-static.com/pdfs/...61ea6520a5.pdf

Tom I know you thought T-Con originally, I swear everytime I had an issue like this it turned out NOT to be T-Con and this time I decided to go with the main board, figures..

Should this chip heat up normally, or could this be the culprit, description being:

The EC5575 is a 14+1 channel voltage
buffers that buffers reference voltage for
gamma correction in a thin film transistor
liquid crystal display (TFT LCD). This
device incorporating a Vcom amplifier
circuits, four rail to rail buffer amplifier
circuits (the highest two stage and lowest
two stage) and 10 buffer amplifiers circuits.
The EC5575 is available in a space saving
48-pin TQFP package, and the operating
temperature is from –20°C to +85°C.

T-con is expensive and hard to locate..

[budm]

Re: Sony KDL-37L4000

That is common failure on T-CON board with AS15 IC.
https://www.badcaps.net/forum/showth...mma#post304275

https://www.badcaps.net/forum/showth...099#post304099

[kevinm34232]

Re: Sony KDL-37L4000

I saw that after searching that part # on here, thanks Bud. I ordered the part I will post back results..

[kevinm34232]

Re: Sony KDL-37L4000

Replaced the AS15-U IC today and that WAS the problem, TV is working with good color. Thanks!

[budm]

Re: Sony KDL-37L4000

Great!, thanks for posting the repair feedback update.