Samsung UN46B7000 sweet scanlines bro!

[Shinju]

So I got this unit and while it turns on no problem the picture was all jacked up.

About 5-6 minutes of letting it sit with a movie playing I hit the menu button and saw that it was on dynamic and switch it and I don't know if it was random coincidence or what, but when I selected Standard the picture when from crap (distortion, some to whoa decent! ( hence the scanlines joke).

Now the screen has faint noticeable lines on it, more noticeable on the left then the right and at viewing distance you cannot really even tell.

I tried the usual tap the screen, flex the bezel (this panel is super thin) and no change, I also left it off over night and when I fired it back up it looked like it did after the first picture you see. OSD is also affected too by these "scanline" deals, the first picture shows the OSD not being affected by the dotted lines going vertical.

I have seen panel tab bond faults and this looks different, I am going to pull the back off and do the T-con/LVDS stuff and get voltage reading as well.

Here are some photos!


First boot up, 5-8 minutes of this and then it was gone and hasn't come back yet. (will try tonight as I have it unplugged)



Panel looks ok but what are these lines!?



Extreme close up!

[selldoor]

Re: Samsung UN46B7000 sweet scanlines bro!

Please can you edit your post and take the inline hosted elsewhere pictures off and repost them using manage attachments so that they remain available in the future as a help to others.

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

fixed, I left the big ones too.

[martino]

Re: Samsung UN46B7000 sweet scanlines bro!

I'm following this for an answer....Do those line go all the way from the left to the right or they fade away towards the right? (got a 55" panny doing this)

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

I'm following this for an answer....Do those line go all the way from the left to the right or they fade away towards the right? (got a 55" panny doing this)

I think they do go across but they are very very very faint on the right side and only noticeable when up-close on a white scene. (EDIT) I did zoom the photo up with Megan Fox and I didn't see any I will snap photo with a solid color screen to be sure.) They almost seem to stop at the end of the OSD boarder.

I left it on for several hours and it looks the same.

Like I said, I flexed the panel pretty hard this unit is super thin and nothing change/flickered or anything.

[tom66]

Re: Samsung UN46B7000 sweet scanlines bro!

I've got one doing this. It's hidden if you turn the brightness down. I'm not sure what causes it. Mine is a 40" A656

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

I've got one doing this. It's hidden if you turn the brightness down. I'm not sure what causes it. Mine is a 40" A656

heh if they were closer together and uniform I would be ok with it, scanlines look slick on video games and this panel supports my XRGB-2 unit.

I have it calibrated with C-nets test calibration the picture on this unit looks damn good for a LED, minus the defect with the lines of course it passed my Avatar and Batman Dark Knight tests

[martino]

Re: Samsung UN46B7000 sweet scanlines bro!

On mine,I replaced the mainboard already(had other problems too) and it did not solve those lines,there is a tcon in the mail today that I will try...tried flexing screen etc too..
will let you know if tcon solved it,if not, Im accepting a "bad panel" answer....

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

On mine,I replaced the mainboard already(had other problems too) and it did not solve those lines,there is a tcon in the mail today that I will try...tried flexing screen etc too..
will let you know if tcon solved it,if not, Im accepting a "bad panel" answer....

That would be awesome, update here I don't mind thead hijack.

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

Ok,

So today it didn't want to bounce out of this funky mode so I broke it down to panel level to see the tab bonds, I took a toothpick and rubbed each of them and no change, if the scree. Is darker these rainbow dotted lines start to fade out, if the scenes are bright these shadow rainbow lines come back and stick around.

Touching the t-con to tab bond board bonds didn't change anything either, unplugging the left or right side only voided the picture per side that was unplugged. The side working still had scan lines and discoloration ect.

Photos inc later on.

[tom66]

Re: Samsung UN46B7000 sweet scanlines bro!

My suspicion is the fault is panel level.

It only occurs on mine with any pixel brighter than about 230/255 RGB. Otherwise, it doesn't occur and the picture is pretty good. My suspicion is it is panel drift due to damage - UV or heat (I'm not sure.) As the panel ages the gate threshold changes requiring different drive voltages. Like a plasma!

One way to fix this is lower AVDD - will require modifying the T-con board.
Another way is to increase VGL (the turn off voltage) - I am not sure if this is possible on these T-cons.

[martino]

Re: Samsung UN46B7000 sweet scanlines bro!

Well,as promised but heavily delayed,I'm reporting back on replacing the T-con board.....
Didn't change a thing,still the same lines
I'm accepting a "bad panel" verdict........

Tom66,you're saying lowering the AVDD? Would you mind elaborating on this?
I'm game to try it ...Should I start a new thread for the experiment?

[tom66]

Re: Samsung UN46B7000 sweet scanlines bro!

It will involve some fairly intricate surface mount soldering and a lot of experimentation if you're willing to try.

[martino]

Re: Samsung UN46B7000 sweet scanlines bro!

let's see,i got 2 T-con boards,a "bad panel" verdict and a whole lot to learn..What could go wrong,lol
As long as it doesn't involve lifting a IC with 1136 legs,as I lack the equipment and knowledge to tackle those...If it fails,it fails,tv was free and I'm sure I can handle a dent in my ego if things go

[tom66]

Re: Samsung UN46B7000 sweet scanlines bro!

OK, post a picture of your T-con, making it clear enough to see AVDD, VGH, and VGL test points.

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

Feel free to use this thread. I know mine is bad if I had the extra funds to toss at another t-con to try I would,but for now it's on the recycle pile!

[martino]

Re: Samsung UN46B7000 sweet scanlines bro!

OK, post a picture of your T-con, making it clear enough to see AVDD, VGH, and VGL test points.

Couldn't get a clear enough pic,so stole one from SJ..I checked and it's identical.
-VGH and VGL I circled.
-Couldn't find AVDD? It has a HVDD and a VDD.

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

that one looks totally different then the one I have installed on mine. The T-con on this panel is massive, almost the size of a small mainboard.

http://www.ebay.com/itm/Samsung-Tcon...item3f3941abf3

[tom66]

Re: Samsung UN46B7000 sweet scanlines bro!

...your Samsung TV has an LG panel? You sure about that?

BTW on Samsung, VGL = VOFFE / VOFF, VGH = VONE / VON

[Shinju]

Re: Samsung UN46B7000 sweet scanlines bro!

FYI, I also did the Test patterns on this one as well and they failed, the DDR ones like the other Sammy I have posted did not show up as well.

When running the test patterns that would work the screen was still bleeding/ghosting and the lines were still present and disappear/reappear.