LG LED 50LB5610: Display blinks

[PatrickSaw]

Hi there!

I have here a brand-new LG 50LB5610, with no warranty due to missing invoice... Well...

Fault: Power up, and display start with the flickering. About 2 seconds picture OK >> 2 seconds screen black >>2s picture OK >> 2s screen black...

I measured the voltage out to the backlight, and it's innestable, but PSU is OK (I have two identical PSU, and I have checked it). So I think I need replace the main board.

Do you think main board is faulty? Or could be the backlight?

Thanks in advance!

[PatrickSaw]

Re: LG LED 50LB5610: Display blinks

Any ideas? I accept even stupid ideas

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

Lose connection with in the Led strips very common, your going to need to take the Lcd module apart to the backlight and get us some images of the array.

[PatrickSaw]

Re: LG LED 50LB5610: Display blinks

Lose connection with in the Led strips very common, your going to need to take the Lcd module apart to the backlight and get us some images of the array.

But I have measured LED+ LED- in the PSU, and it has unstable voltage. And it must be stable... isnt it?

[Diah]

Re: LG LED 50LB5610: Display blinks

But I have measured LED+ LED- in the PSU, and it has unstable voltage. And it must be stable... isnt it?

unstable voltage mean you have shorted LED...

[PatrickSaw]

Re: LG LED 50LB5610: Display blinks

Lose connection with in the Led strips very common, your going to need to take the Lcd module apart to the backlight and get us some images of the array.

unstable voltage mean you have shorted LED...

You were right!

I have disassembled and checked the display and strip LEDs: a LED segment is faulty. So now I need replace that segment, because I suppose it's impossible to fix a strip LED...

Thanks very much to both! I would have never found this fault without your help.

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

No it is easily possible check this out:

https://m.youtube.com/watch?v=Bf5T2wwtydY

[PatrickSaw]

Re: LG LED 50LB5610: Display blinks

No it is easily possible check this out:

https://m.youtube.com/watch?v=Bf5T2wwtydY

Hello again.

Great video. But I cant find a Led for the strip... I have read your advice, about not short the faulty led. You talk about replace the Led with a 1w SMD type, or sub it with a resistor or diode. Could you tell me a little more about that? I have doubts in type of diode, or what resistance value use.

Thanks again in advance!

[Diah]

Re: LG LED 50LB5610: Display blinks

Hello again.

Great video. But I cant find a Led for the strip... I have read your advice, about not short the faulty led. You talk about replace the Led with a 1w SMD type, or sub it with a resistor or diode. Could you tell me a little more about that? I have doubts in type of diode, or what resistance value use.

Thanks again in advance!

you can buy one lot 100 pieces from China, at aliexpress.com for just less 3 USD include post

3528 2835 SMD LED 1W LG Cool White
Model Number: LATWT470RELZK
Brand Name: LG
Forward Current:400mA
Size:3.5*2.8*0.6mm
lumens: 100LM
Forward Voltage:3.05-3.65V

[budm]

Re: LG LED 50LB5610: Display blinks

Can we see the pictures of the LED strips in your TV?

[PatrickSaw]

Re: LG LED 50LB5610: Display blinks

Can we see the pictures of the LED strips in your TV?

Yes of course! It lights on 4-5v.

[budm]

Re: LG LED 50LB5610: Display blinks

Ah yes, those are commonly failed LED type.
LG INNOLUX LEDs
Luckily it is Back-lit not Edge-lit.
Once you get it fixed you should turn down the Backlights level in the on screen user menu as low as possible to extend the LED's life.

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

Why is it lucky ? You can sub them Leds with 0.5w ultra bright SMT type off Ebay.

[budm]

Re: LG LED 50LB5610: Display blinks

More room on the backlights LED strip than the Edge lit strip which LEDs are crowded together.
I would go with 1W, 0.5W is less than 200 mA current limit, some of these strips are driven with more than 200mA, not much room for margin with 0.5W LED.

[PatrickSaw]

Re: LG LED 50LB5610: Display blinks

Ah yes, those are commonly failed LED type.
LG INNOLUX LEDs
Luckily it is Back-lit not Edge-lit.

You mean I could replace the faulty LED only with a resistor?

Once you get it fixed you should turn down the Backlights level in the on screen user menu as low as possible to extend the LED's life.

Roger that.

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

More room on the backlights LED strip than the Edge lit strip which LEDs are crowded together.

Ahh I see, yeah I agree replacing edge lit type leds is very hard. I have a youtube video uploading now about me repairing this type of Led strip. Will create a tread on it tomorrow.

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

You mean I could replace the faulty LED only with a resistor?




Roger that.

Yes I think user Tom66 uses a 0.5w 2.2 ohm type to sub a bad led. I will get the thread for you.

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

Here is the thread:

https://www.badcaps.net/forum/showth...ghlight=Ves315

[budm]

Re: LG LED 50LB5610: Display blinks

400mA of driven current! made to fail.

[ReeceyBurger123]

Re: LG LED 50LB5610: Display blinks

Yep