Samsung UE46C8000 Horizontal Dark Lines across screen

[DemonBG]

Hi All,

So i picked up this set yesterday thinking it may be a T-Con / Main board issue given the regularity of the lines across the screen...

Symptoms:
As you can see from the pictures, it has perfectly straight, equally spaced horizontal bands which are "off colour" the full length of the screen and across the full height.

Apparently this originally started only when the set was first turned on and then disappeared over a few minutes but got more regular / persistent over time - This makes me think it could be heat related?


Fortunately i have a working UE46C7000 which i think uses the same boards (Can anyone confirm if the boards are the same?) so hope to be able to diagnose boards with that...

Does anyone have any recommendations of what to check?

Regards,
Demon

[tom66]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

It will probably be panel or T-con.

To eliminate main board you can go into the service menu and check test patterns, there should be three. If the fault occurs on all of them, it will be panel or T-con at fault.

Then... it's a crapshoot. We've seen quite a few panel failures that looked just like this so beware of the possibility.

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Thanks for the reply Tom. It looks very similar to some of those panel failures I have seen so will run the tests when I get a chance and then report back. I'm not going to hold my breath as I have a suspicion it may be panel failure....

Will keep you posted.

Really appreciate the help.
Demon

[mmartell]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

There is a member here who has had some success repairing this type of failure he says with a - wait for it - dremel tool. I for one am interested to see exactly what that's about.

[mmartell]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

The members name is freakaftr8, maybe he will chime in here.

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

All we can do is hope! Haha. I would be skeptical, but in this day and age - what can't you fix with a Dremel!!

[mmartell]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

He started his explanation by saying "you will think I'm crazy, but...". Doesn't mean I'm not curious. After all there may be a rational explanation for the voodoo behind it lol.

[tom66]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

It might work on some panels which have tab drivers on both ends, such as early 1080p and 100/120Hz panels. By removing one driver that might be loading down the drive signal, you could stop the horizontal banding, they are essentially in parallel. However, I suspect there is a good reason for having two drivers so this might just lead to premature failure of the opposite drive pair.

Never tried it myself, maybe I'll try it if I get desperate.

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Hey Tom,

If i whittle the problem down and confirm it being the tab Driver i will give it a go. I will also slap a large amount of thermal pads on the remaining driver to try and make it last as long as possible... If it really is the Tab Driver - What have i got to lose!? :P

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Tom,

Im starting to look around for a replacement T-con Board and beleive the part number is:

2010_R240S_MB4_0.5

Am I correct in saying that the very last number (0.5) is usually the revision number and should be inter compatible? (i.e. if i got a 2010_R240S_MB4_0.4 should it still work?)

Regards,
Demin

[tom66]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

If all the connectors are the same it -should- work... Samsung sets usually aren't picky.

[tibimakai]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

C series, usually has bad mainboards, no?

[tom66]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

C series, usually has bad mainboards, no?

Doesn't mean they don't have bad panels. It is an LCD TV after all. Any LCD 2008 onwards has a risk of bad panel, it just gets even worse 2010 onwards.

[Shinju]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

What did the service menu tests patters tell you?

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

ok this is a very odd symptom but the test patterns do... Nothing! as in, absolutely nothing... I have 3 options:

"Reading PC Mode"
"FRCS OC mode"
"FRC200 PC Mode"

But when set each / all to "on" absolutely nothing happens - No test patters show up or anything... not sure if this is normal behaviour or if i need to do anything else?

Whats even more odd is that in the SVC menu there is a setting called "Panel Auto setting" and "T-Con USB Download" which are both set to "Failure" and cannot be changed... Any idea what this is about?


Regards,
Demon

[Shinju]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Have you downloaded the latest firmware? I have ran into some sammys that had what you are seeing and downloaded the latest FW and they showed up and worked.


There is another remote command you can do when inside the SVM the opens up extra stuff. For the life of me I cannot remember it.

[Shinju]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Don't worry about USB t-con failure I never seen that pass and the panels have worked fine.

[tom66]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Think it's related to plasmas which can update the control/tcon firmware over USB.

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

Should I worry about the "panel auto failure". .?

[DemonBG]

Re: Samsung UE46C8000 Horizontal Dark Lines across screen

ok so i updated the firmware to the latest version but still nothing from the test patterns... What does that suggest?

Update 2: I followed the same procedure on my UE46C7000 (which i think is the same TV with a different frame...) and i cant get test patterns to show on that either... and that is a working tv!