LG 50LF5800-UA Backlights flicker on and off

[Jackching]

So i ran tests on the power supply and all of the voltages going to the main board are fine. I tested all of the capacitors on the psu with an esr reader and they all pass. All diodes pass also. But when a reading is done on the 4 pin white led connector on the top of the board, the voltages will flicker to 5Vdc for a fraction of a second and go out again. For that fraction, the LED backlights light up. Anyone have any clues to this situation?

[neilc6]

Re: LG 50LF5800-UA Backlights flicker on and off

Quick flash of backlights or flashing backlights are both symptoms of bad backlights. Especially on LN, LB or LF series.

https://techhometravel.com/lg-ln-ser...ed-backlights/

[dick_barton]

Re: LG 50LF5800-UA Backlights flicker on and off

If your leds flicker then you must have a high voltage at the connector in order to light them up. The voltage may sharply spike at switch on and then drop quite rapidly.
Recheck the voltages at each pin to chassis at switch on and repeat for all four pins.
Quite can't see what is given on the circuit board but it looks like one set of leds run at 113V and the second set at 170V

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

Quick flash of backlights or flashing backlights are both symptoms of bad backlights. Especially on LN, LB or LF series.

https://techhometravel.com/lg-ln-ser...ed-backlights/

Unfortunately i think you are correct. I think this tv may go to the sidewalk or are there cheap led string replacements for the 50LF on aliexpress?

[neilc6]

Re: LG 50LF5800-UA Backlights flicker on and off

About $32 USD on ebay from China.

[handsworth]

Re: LG 50LF5800-UA Backlights flicker on and off

About $32 also on Ebay. Purchase from any one of the guys from Tucker, Ga. They get them from China and stock them in the US. About 4 days delivery time

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

What are you guys typing in to find these for this model?

[nomoresonys]

Re: LG 50LF5800-UA Backlights flicker on and off

There, notice the two for 32 dollars are from the U.S., look at compatible models in their description: https://www.ebay.com/sch/i.html?_fro...acat=0&_sop=15

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

Would this be the right one for 50LF5800: https://www.aliexpress.com/item/4000...63504c50BkNUaT

Nine LEDs per row with five rows?

[nomoresonys]

Re: LG 50LF5800-UA Backlights flicker on and off

Those should work, says direct replacement for those models in description.

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

Ok so these LEDs worked fine but i ended up breaking about half of the clips off that keeps the white panel from touching the leds. Anyone know what these are called so i can order new ones? I can see the round shape of the led covers on the screen when watching tv.

[nomoresonys]

Re: LG 50LF5800-UA Backlights flicker on and off

You mean the plastic standoffs?

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

Whatever is in the picture there. They're called standoffs are they? Go to 7:40 in this video: https://www.youtube.com/watch?v=s4wNc3hF4JI

[handsworth]

Re: LG 50LF5800-UA Backlights flicker on and off

I remove mine from the back of the panel. Push down on skinny part of tab and slide back.

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

I remove mine from the back of the panel. Push down on skinny part of tab and slide back.

Ya well it's too late for that. Half of them are broke now. Looking for a place to purchase them

[handsworth]

Re: LG 50LF5800-UA Backlights flicker on and off

I got lots of extras but dont know how to ship to Canada or what it would cost.

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

I can see the leds through the screen in a few places when watching tv. Im assuming its because of the few broken standoffs right?

[dick_barton]

Re: LG 50LF5800-UA Backlights flicker on and off

Could you have glued the broken standoff's. Superglue or something similar.

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

Could you have glued the broken standoff's. Superglue or something similar.

I could try that with hot glue or something

[Jackching]

Re: LG 50LF5800-UA Backlights flicker on and off

So anyway i put all the broken standoffs back on with glue but can still see two leds shining through the screen when it's on. It's like they are brighter then the rest or something. They are especially visible when there is a lot of white on the screen in those areas. I cant figure it out. I got them from aliexpress. Maybe they're faulty. Is it possible to put the light filters back in upside down?