samsung ue55ju6800 problem with brightness

[george_gpu]

good day
It has difference upper , rearmost has 1/4 of the normal brightness
first photo is with problem ,second is after reflow tcon but last for 5 days only
https://we.tl/t-iXPSvuEpQP

It is tcon or panel fault (cof bad ) ?

[nomoresonys]

Re: samsung ue55ju6800 problem with brightness

Try uploading pictures here, not dealing with unfamiliar sites.

[george_gpu]

Re: samsung ue55ju6800 problem with brightness

Goodmorning i attach photo

[budwich]

Re: samsung ue55ju6800 problem with brightness

gamma chip problem... maybe.

[george_gpu]

Re: samsung ue55ju6800 problem with brightness

AS15 F ?
but only make problem in up area of panel ?

[budwich]

Re: samsung ue55ju6800 problem with brightness

input a test screen for gamma and you will see what the result is.

[george_gpu]

Re: samsung ue55ju6800 problem with brightness

you mean menu\support\selfdiagnosis\picture test ?

panel is:55B6AU0TJ

[george_gpu]

Re: samsung ue55ju6800 problem with brightness

Good day check after the test

[nomoresonys]

Re: samsung ue55ju6800 problem with brightness

Are you using hdmi? can try different hdmi cable or other source like dvd player or just over the air antenna, sometimes a cable box reboot helps, could also be bad leds, make sure you have a good connection of lvds cable from tcon to mainboard.

[george_gpu]

Re: samsung ue55ju6800 problem with brightness

This is with tv antenna ,lvds i ckeck it ok.
You think it has low bright from up led bar ,i have to take off panel for tets it?

[nomoresonys]

Re: samsung ue55ju6800 problem with brightness

That would be my guess, could try testing the backlights before you take it apart, have to be VERY careful with the panel, they are flimsy and very easy to break.

[nomoresonys]

Re: samsung ue55ju6800 problem with brightness

Here's some basic testing on a samsung un32, not your exact model but it gives you the info on how to test. https://www.youtube.com/watch?v=EgRKJAqYqeo

[budm]

Re: samsung ue55ju6800 problem with brightness

Can we at least see the pictures of the whole backside of the TV showing all the boards?
What is the power supply board P/N? BN44-??????
You need to do basic Voltage checking first.

[jjanssen7]

Re: samsung ue55ju6800 problem with brightness

FYI- In my experience this model has a problem with backlights that when one of the leds fail it can have a display like that.

[budwich]

Re: samsung ue55ju6800 problem with brightness

so "reflowing the tcon" somehow causes the backlights to work ok... :-) not sure how that happens.

[nomoresonys]

Re: samsung ue55ju6800 problem with brightness

so "reflowing the tcon" somehow causes the backlights to work ok... :-) not sure how that happens.

That is a MAJOR heas scratcher

[budm]

Re: samsung ue55ju6800 problem with brightness

https://www.shopjimmy.com/samsung-bn...-con-board.htm
More likely that the T-CON controls the backlights level for the two LED strings for the Dynamic contrast function via connector CN500.
That is why it is important for OP to provide the pictures of what we are dealing with.

[jjanssen7]

Re: samsung ue55ju6800 problem with brightness

It is a curious problem with these models, I've never had one that the tcon fixed the brightness problem but I never really tried too hard. I have new tv's with cracked screens and swapping the panel always does the trick. When I do that, I pull apart the original TV and most often find a burnt LED.

I'm curious about the reflow tcon though because I've had one or two that worked sometimes then not other times. I assumed that it was because one of the LEDS was on the way way out (they were always high hour TV's), but I suppose a failing tcon could cause the same end result. I'll be following this thread with interest.

[budm]

Re: samsung ue55ju6800 problem with brightness

Hopefully the OP will come back and show us some pictures and some Voltage testing.

[budwich]

Re: samsung ue55ju6800 problem with brightness

I am still curious also though. If it was a string issue, then supposedly this set is edge lit then how does the test pattern with the gradients light somewhat in the borders at the top but have such a nice "boundary" of "lost brightness " in his first display.... doesn't seem right for a led display issue versus a problem elsewhere.