Samsung UE55JU6800 Issue with new backlight

[kdaniel]

Hi all,

Recently bought faulty Samsung UE55JU6800 which when collected was faulty and was not turning on or at least there was jo picture on it. After taking it home and turning it on the TV was working fine.

However, there were dark spots all around just like faulty backlight looks like. After replacing the backlight for new one, there is the same issue where black spots can be seen at the point of each led.

Any advice ore recommendations what could be the possible issue? Could it be cheap backlight i got from china?

Thanks in advance.

[nomoresonys]

Re: Samsung UE55JU6800 Issue with new backlight

looks to me like you wound up with junk replacement backlights, you have the diffuser sheets in the right order?

[kdaniel]

Re: Samsung UE55JU6800 Issue with new backlight

I placed back diffuser sheets back as they were, yes. Even tried different order to see if anything changes without luck. Only thing I could think of are cheap backlight strips I got.
Never had such a problem before with other TVs but always had bad luck with repairing Samsung TVs

[nomoresonys]

Re: Samsung UE55JU6800 Issue with new backlight

it is strange, it kind of seems like the lenses are not letting the light out properly? did you compare the strips to your old ones?

[kdaniel]

Re: Samsung UE55JU6800 Issue with new backlight

It seems like that... Do you mean if I compared the model numbers or something else? I believe I ordered per model number of the strips. By the way, this is the first time I ordered strips directly from china, AliExpress to be more precise...

[Storyteller12]

Re: Samsung UE55JU6800 Issue with new backlight

Did you put the plastic stand-offs back on? I’ve seen them melt from the heat also and cause the diffuser sheets to sit lower and cause this issue

[kdaniel]

Re: Samsung UE55JU6800 Issue with new backlight

@Storyteller12 yes, all plastic stand-offs are back in place. I didn't see any melting when I was replacing the backlight. I've seen that too before but this one is new to me that every single LED is visible as a black spot

[Storyteller12]

Re: Samsung UE55JU6800 Issue with new backlight

Yeah me to. Never seen everyone like that unless stand-offs were missing or melted.

Has to be the lens on backlights were not placed correct from factory then.

[R_J]

Re: Samsung UE55JU6800 Issue with new backlight

Is it possible the first thick diffuser is reversed? There should be a smooth side and a rough side, which side is toward the led's?

[kdaniel]

Re: Samsung UE55JU6800 Issue with new backlight

Has to be the lens on backlights were not placed correct from factory then.

That is what I am thinking as well. I attempted fixing single LED diodes before and I do know how easy is to misalign the lenses. If they are not perfectly centered they are visible as dark circles. But dark circles and these darks spots are completely different.

I am now really thinking to order another set of backlights here from the UK and see if that changes anything.

[kdaniel]

Re: Samsung UE55JU6800 Issue with new backlight

Is it possible the first thick diffuser is reversed? There should be a smooth side and a rough side, which side is toward the led's?

I cannot confirm which side is facing LEDs but I remember I tried rotating it and it made no difference to me.

The sad story is that I already took apart this TV 2 times and I think it will need the 3rd one as well.