Help with 26LG30-UA

[ragingfish]

Hi everyone -

I've been searching everywhere trying to figure out how to diagnose this TV, but have come up empty. I'm hoping someone here can help!

I have a 26LG30-UA that's giving me problems...again. The first issue I had was about 2 years ago and I replaced some bad caps on the power supply and all was well.

The new issue is more than just bad caps. There WERE bad caps, and I replaced them, but continue to have issues. In addition, I sourced out another power supply, just in case, but that is not the solution.

I've read online that the UA models are problem prone.

What is happening is this.

I plug in the TV, the blue power LED flashes as if warming up, as it always has. It takes longer than usual however. Then, I see the backlight come on, but no picture. There is also no sound. If I try to turn the TV off, from when I press the power button, it takes bout 10 seconds to shut off again, whereas in the past it used to be instantly.

I've tried changing modes or pulling up menus with the remote on the off chance the keypad went bad. I see the blue LED flashing in response to remote commands, but there is no change to the screen.

So I know the power supply is ok, and I know the backlight is ok. I am assuming the tuner is NOT the issue because I can't even get the OSD to come up.

Can anyone shed some insight on how to repair this? I'm comfortable swapping components on boards and would really like to fix this TV on my own.

Thanks in advance for anyone's help!

Mike

[ragingfish]

Re: Help with 26LG30-UA

**bump**

Anyone able to shed some insight on this?

[budm]

Re: Help with 26LG30-UA

First: we need good clear pictures of the back side of the TV so we can see how the boards are connected together. Please make sure to use managed attachment to upload the pictures, do not post in line.
Second: Did you use low ESR type caps for the replacement?
So the backlights stay on all these time with slight glow on the screen? If that is the case, then we need to check the DC voltage on both ends of surface mounted fuse on the T-CON board.

[ragingfish]

Re: Help with 26LG30-UA

Thanks so much for your response!

Requested picture is below.

As for caps, I bought a rebuild kit from lcdalternatives.com which is actually how I discovered this site. I don't honestly know what low ESR caps are, so I'm not sure if that's what he sells or not. Would they be marked in such a way to identify them as such?

Can you help me identify which is the T-CON board so I can check those voltages?

Thanks again!!

PS - Disregard the detached transformer, it's an older pic, I've already corrected that lol.

[Mr Bill]

Re: Help with 26LG30-UA

Here is where your tcon is located. Did you remove it before because it looks like it's upside down.

[ragingfish]

Re: Help with 26LG30-UA

No sir, never touched it before.

[Mr Bill]

Re: Help with 26LG30-UA

was it picked up used? Typically all the smd components are facing out.

[ragingfish]

Re: Help with 26LG30-UA

Nope. I'm the sole owner and done the only work on it which to date consists only of swapping caps on the power supply.

[Mr Bill]

Re: Help with 26LG30-UA

wow. I've never seen a tcon placed like that in a chassis. You are going to have to flipped the tcon board over and look for the fuse. The fuse will have a "F" in front of the number (F1, F2). Can the board be flipped over and hooked up? If not the only test you could do is check resistance.

[ragingfish]

Re: Help with 26LG30-UA

i shall give it a shot and report back!

[ragingfish]

Re: Help with 26LG30-UA

Ok, I was able to flip it while connected I only see one onboard fuse and I got 11 and change on both sides of it.

[Mr Bill]

Re: Help with 26LG30-UA

was this with the tv on? So 11.xx volts?

[ragingfish]

Re: Help with 26LG30-UA

Yep, unit on, it was 11.8-something.

[Mr Bill]

Re: Help with 26LG30-UA

The fuse on the tcon is good. Can you remove the metal sheild that is covering the main board and take a good close up photo of it so we can see if there is anything that can be checked.

[ragingfish]

Re: Help with 26LG30-UA

Not sure which board you meant so i did both

[budm]

Re: Help with 26LG30-UA

Can you take the pictures of the component side of the T-CON board, I think you have bad T-CON.

[ragingfish]

Re: Help with 26LG30-UA

Attached

[ragingfish]

Re: Help with 26LG30-UA

Stupid question - what does T-CON stand for?

[budm]

Re: Help with 26LG30-UA

Timing Control.

[budm]

Re: Help with 26LG30-UA

OK, you will need to check the voltages at the test points on the T-CON board. If you look real close at the board, you will see exposed round copper pads with white circles.
Please check these points:
V3D3
V1D8
VGL
AVDD
VGH
VGHC

And also the readings on all 3 pins of U200.
The T-CON is about $40.