Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

[Thomtech]

I have an interesting problem that I will attempt to describe and hope someone can guide me in the right direction to troubleshoot and repair.
All input sources display the same issue in which the video is blurred like the TV is on LSD, as the moving picture is a rainbow of swirling colors. A static picture looks perfect. When another static picture is loaded the old one slowly fades away (10 sec.) as the new one becomes visible.
I have background in electronics repair and design so I also have high hopes that this can be repaired and with a little help it could be a short time to find the problem.
Thanks in advance :^)
Thom

[tom66]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

My guess would be tab bonds/bad LCD panel.

[ajshoe]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

AGREE - tab bonds. have to take LCD panel out of frame and play with tab bonds til u find the culprit. then massage "bumper" in correct position with metal frame back on to "fix" picture. Easy fix but takes time (don't rush job or you'll being doing it again). had good luck with "fixes".

[Thomtech]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Thanks for the quick reply from Tom66 and Ajshoe and now I will have to do some research as to what "tab bonds" and "bumper" are. Is this
'play with tab bonds' activity spelled out somewhere? Working on LCD TV is one of the very few electronics products that I have very little experiance with, but the solution sounds like there is hope.

[budm]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Example of TAB bond repair:
https://www.badcaps.net/forum/showth...LN52A530P1FXZA

[stj]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

not so sure,
i'm sure it's the lcd panel - but it sounds like the bias voltage is missing or something.

[budm]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Show us the screen shot of the TV.

[Thomtech]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Thanks for the suggestions. From what I understand about this "tab bond repair" is really just getting the heat removed from the components by conduction to the LCD metal mounting frame. While this may be generally required, I see the problem before any heat has built up.
I also just noticed that the static picture is very dark even with brightness turned up.
Switching from one static picture to another is seems the picture shows "On" fast but when next picture is selected the old one leaves slowly over about 10 sec.
I am thinking some voltages need to be checked first. Any suggestions are welcome to make this repair as efficient as possible and with all the experience here I think someone has likely seen this problem before.

[tom66]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Tab bond repair isn't about heat removal; it's trying to "shim" the bond into making good contact with the panel board or LCD.

[ajshoe]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

please post a pic of set on. another test is with set on - twist or flex set and see if pic changes. not a quarantee but sometimes will be able to see change.

[Thomtech]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Tab bond repair isn't about heat removal; it's trying to "shim" the bond into making good contact with the panel board or LCD.

Then making the better contact is an electrical enhancement?

[tom66]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Then making the better contact is an electrical enhancement?

Yes

[Thomtech]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

Thank you for making that clear for me. Understanding the Terminology and application is the one thing that often becomes unique among the various products and engineering disciplines. Each support group develops their own set of terms which get taken for granted by the professionals in that field, but must be understood by those who enter or try to be productive in that field.
This reminds me of the first (original) LCD (dot matrix) that I worked with in the early '80 was made of glass with the electrical interface to the matrix bonded to the glass. The LCD electrically interfaced with the drive circuits mounted on a PCB with what was called a "zebra strip" which was a flexible strip of material that had lines of conductive carbon and rubber/silicon. The strip positioned between the display and PCB fingers/lines and all interface signals passed thru it. This bonding tab is sorta the same thing it seems.

[tom66]

Re: Samsung TV (LNS3251DX/XAA) Display Blurry with Motion

The issue with zebra strips is they don't have the required density to connect to modern large LCD panels; a direct connection, a tab bond, is necessary.