samsung LNT4069FX/XAA poor pic quality and fading

[jose6326]

I picked up this set at a garage sale for 20 bucks
I figured it wasnt much to try to fix it

Anyways when I power it on the pic quality is poor and when I change the channels it fades to the left
When I change the channel the previous image is left behind then the new image catches up

Hopefully im making some sense and you guys understand me

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

I found a couple of bad caps on the psu

I ordered new ones so hopefully I get these by Saturday

What else should I test or does anyone know the problem?

[Shinju]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Almost looks like bad tab bond issue, I got a sony doing that. Change the caps for sure but that's a image processing issue t-con/mainboard/panel.

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

I was afraid of that. I will post an update once I replace the caps

[aaronwt6]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Almost looks like bad tab bond issue, I got a sony doing that. Change the caps for sure but that's a image processing issue t-con/mainboard/panel.

Agreed. I'd bet on tab bonds. Although, I've had very good success repairing both the 40" and 46" version of these Samsung panels from that era with shims on the suspected bad tab.

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Ok so I replaced the caps and I still have poor picture quality and fafing to the left when I change the channels

So should I take it down to the panel and press on the tab bonds or should I test other components before I do so?

Thanks for the help

[tom66]

Re: samsung LNT4069FX/XAA poor pic quality and fading

For sure, that is a bad panel/tab bond issue, so you will need to take it down to the panel to see if you can fix it.

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Thanks tom

Once I take it down to the panel do I just press on each tab bond to see if there are changes?

If it is a tab bond what can I use to keep pressure on the tab bonds?

Thanks

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Ok so im back on this tv

I have taken off the plastic bezel and have removed the screws from the metal frame

Are there only tab bonds on the top?
Do I have to fully remove the metal frame?

So do I just press on these with my fingers?

[AFajitas]

Re: samsung LNT4069FX/XAA poor pic quality and fading

You can press them with a piece of cardboard or something. They get pretty hot. If you find one that makes the image change, power the tv off and back on while applying pressure to it and see if it makes a difference.

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Ok so I pressed on the tabs where they make contact to the board.
There was no change in picture quality as you can see from the pics
There is still double images

Also what about the tabs on the side of the panel?
Do they do anything?

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

As the tv warmed up it developed horizontal lines
These were not there before

When I change the channel they go away but reappear once the image shows

[AFajitas]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Jose, this is a tab bonding issue for sure. I can see the lines that separate the areas of the screen that each tab controls. The ghosting is also a symptom. It seems once the ghosting starts, the TV needs to be power cycled before it will correct itself, even if pressure is applied to the proper tab. My samsung has the same issue. I had to play around with the tabs for quite a bit before I got any results. I managed to get it working, but still have one of these annoying lines in the screen. It seems from my reading that it is usually either the top left or the top left tab that is affected. In my case it was the top right (if you are facing the screen). I actually have to apply pressure to the part of the cable between the screen and the controller board to make a difference.

[AFajitas]

Re: samsung LNT4069FX/XAA poor pic quality and fading

I can make a video for you if you want, as I still have the TV stripped down.

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

I would appreciate it

Please show how you applied pressure and where

I know im doing something wrong

[jose6326]

Re: samsung LNT4069FX/XAA poor pic quality and fading

No need for the video

I found the faulty tab bond

It is the top left when you face the screen

It is actually the part that connects to the panel

Thanks

[budm]

Re: samsung LNT4069FX/XAA poor pic quality and fading

This how I did my tab bond repair:
https://www.badcaps.net/forum/showpo...&postcount=113

[AFajitas]

Re: samsung LNT4069FX/XAA poor pic quality and fading

Wow, what a night. I took my Sony KDL-52VL150 with the tab bonding issue apart to take pictures and post them here only to find that the problem persisted after removing my make shift electrical tape pad and reapplying it. I then spent two painful hours removing and remounting the metal frame and touching various parts of the tab trying to get rid of the ghosting but to no avail. I was pretty sure I broke it permanently at one point. Finally, I pinpointed the exact area where I need to apply pressure and I fixed it once again by readjusting the position of my padding. I just rolled up a 4 inch length of electrical tape into a small wad and then electrical taped that to the inside of the metal frame making sure to line it up with the spot highlighted in my pics. Too tired to post any more pics or the video, might do it tomorrow. Still have a small 1 pixel line that goes halfway across thescreen that is bearable. I suspect it's a single failed trace on the tab that Im not going to be able to fix. Also getting some slight noise in the panel that comes and goes, subtle rolling horizontal waves that are most noticeable on light backgrounds. I am making my wife and kids use this as their main tv until I fix it completely or part it out. It's still very watchable but I'd feel weird trying to sell it like this.

Here is a video of the issue before it was fixed: http://youtu.be/Dg8EmAnLAOk

[AFajitas]

Re: samsung LNT4069FX/XAA poor pic quality and fading

No need for the video

I found the faulty tab bond

It is the top left when you face the screen

It is actually the part that connects to the panel

Oh, I just saw your reply after posting! Exact same area as me, how funny.

[budm]

Re: samsung LNT4069FX/XAA poor pic quality and fading

I fixed that one two years ago, I am using it every day in my living room.
http://s807.photobucket.com/user/bud...?sort=3&page=1