Samsung TV display deterioration

[PrimalR0de0]

I have a Samsung LN46B640R3FXZA. It is somewhere around 4 years old. It resides on a TV stand, so there is nothing around or near it as far as ventilation restriction. The picture quality has recently started deteriorating after the TV "warms up". It will display perfectly fine for a few minutes (sometimes 10 or 15 minutes), and then the picture will slowly turn into what looks like a photo negative and becomes dark and grainy. It does this on all inputs and input sources (cable box, DVD player, media streamer... two are HDMI, one is composite), and the deterioration also affects the TV menu, so it would appear to be the TV display and not an input. Once this deterioration occurs, after turning off the TV and immediately turning it back on, it will display properly for only a few seconds before rapidly repeating the problem. Any suggestions on what may be the cause? Thank you in advance!

[tom66]

Re: Samsung display deterioration

Can you provide a picture of the fault when this occurs?
Does it suddenly "snap" and it's bad, or slowly flicker in, or fade in?
When it fades/flickers, does it fade/flicker in bands or all the screen at once?

[Brass eagle]

Re: Samsung TV display deterioration

My brothers samsung has started playing up like this one but its not a fading picture this one shows the screen quite pale and is displaying green vertical lines,I am wondering if its the same sort of problem waiting to develope

[tom66]

Re: Samsung TV display deterioration

@Brass I think that is an LCD panel failure, leaking layers. Never seen that before, though, very odd.

[PrimalR0de0]

Re: Samsung TV display deterioration

In this instance there was and is no "forewarning", just a gradual fade over a relatively long period of time (a few minutes initially, but then within about 20-30 seconds while the TV is still warm). I've had the TV off, so I just fired it up and it's running right now... I'll post a pic of the problem shortly.
Thank you for your time, Tom.

[PrimalR0de0]

Re: Samsung TV display deterioration

Here are the before and after pics of the problem. Sorry about the angle, the tv is already on my workbench rack (thus the wood slat in the pics). Also ignore the shadow in the upper right corner, that's the case for my tablet coming into view of the camera lens.

[tom66]

Re: Samsung TV display deterioration

This looks like GAMMA chip problem. You can test this if you have a multimeter. If you find the board bad you can send it off to repair, around $50, or buy a replacement. If you're competent with surface mount soldering, or know someone who is, you can repair it for about $4 (AS15-F chip replacement.)

First post a picture of the back of the TV with the case off.

[PrimalR0de0]

Re: Samsung TV display deterioration

How would one go about testing one of these?

Here is the back of the TV.

I've done quite a bit of surface mount soldering, but I guess everything is relative, so it depends on your definition of "competent" lol

[budm]

Re: Samsung TV display deterioration

Bottom center is the metal shield which where the T-CON board is, you need to remove the shield and make sure to use the screws to mount the board back in place without the shield.
There is a white sticker (close to the top center) on the chassis which is the make and model of the LCD panel. Can you give me the info on that sticker?

[tom66]

Re: Samsung TV display deterioration

OK, right at the bottom of the LCD panel, with the orange wire running to it, you have the T-CON board. Remove the shield from this and get a picture of it. Looks like this TV uses AUO panel (AU Optronics) which has common issue with AS15-F.

edit: Budm beat me by a minute.

[PrimalR0de0]

Re: Samsung TV display deterioration

Yeah, I figured you were gonna say that once I realized that I hadn't removed that panel. Here's the T-CON board.
It is AU Optronics, model T460HW03 V.8

[tom66]

Re: Samsung TV display deterioration

Test these points VGMA1...22 (I think?) The copper pad near each needs to be tested.

Do one test before it gives the fault, and one after, if possible.

That chip above the test points: get the part #. That will be the one that needs replacing.

[PrimalR0de0]

Re: Samsung TV display deterioration

Good work gentlemen! I took the easy (and more importantly, faster) way out and replaced that whole board, which I found used for about $70. TV works like a champ now! Thank you both for your professional insight.

[brucetv]

Re: Samsung TV display deterioration

Tom66
What meter reading do you use and what kind of voltages should you see on those test points? Thanks

[budm]

Re: Samsung TV display deterioration

Tom66
What meter reading do you use and what kind of voltages should you see on those test points? Thanks

DC Volt.
https://www.badcaps.net/forum/showth...667#post585667

[Shane711]

Re: Samsung TV display deterioration

I picked up one of these TVs yesterday. Samsung LN46B640R3FXZA. Thought at first it was the display but the tabs(Ribbon Cables) seem to be perfect, nothing spilled on them and no signs of damage. After touching and rubbing the tabs there is no change. However when playing a movie the lines on the screen seem to change when the pictures change. There are also lines going across the entire screen. Like every other horizontal pixel line is off. 1 on the next off, the next on and the next off and so on. You can see that in the second picture if you look closely. So I am assuming it has to be the Main board or T-Con board. I do not have any parts for this to swap out so I can only guess for now. Has anyone had this experience?

[Shane711]

Re: Samsung TV display deterioration

Well I found a Samsung LN46B610A5FXZA laying around. All the parts were interchangeable with the Samsung LN46B640R3FXZA so I was able to determine I had a bad screen. Man this bites. And the LN46B610A5FXZA had a bad screen, bad main board, and a bad power supply. The power supply I will fix. Another 2 TVs bite the dust. I just got back working on TVs because I had to move all my stuff at the end of October 2015 so it has taken me this long to get back on track. I got about 200 more sets to work on.

[ivtec]

Re: Samsung TV display deterioration

Well I found a Samsung LN46B610A5FXZA laying around. All the parts were interchangeable with the Samsung LN46B640R3FXZA so I was able to determine I had a bad screen. Man this bites. And the LN46B610A5FXZA had a bad screen, bad main board, and a bad power supply. The power supply I will fix. Another 2 TVs bite the dust. I just got back working on TVs because I had to move all my stuff at the end of October 2015 so it has taken me this long to get back on track. I got about 200 more sets to work on.

Shane can you please tell me if this Samsung LN46B610A5FXZA has any of these Panel assemblies #'s ? LTY460HB10-001
LTY[Z]460HB11-A02

[Shane711]

Re: Samsung TV display deterioration

Neither one of those numbers match what I have. I am curious as to why you asked? It seems maybe I could have fixed one of these but I didn't want to bother with it because the chances of succeeding might be too low. I have included pictures of the Panel stickers.

[martino]

Re: Samsung TV display deterioration

I got about 200 more sets to work on.

200? Due tell where you got them all from
I'm trying to get as many as possible,but the struggle is real in doing it.