Earliest Led Tv Backlight Failure Yet Please Read.

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

did you put the diffuser and polariser sheets back in in the exact order and orientation they came out?
that can cause odd symptoms.

I did yes, I think that its because of the horrible contrast ratio and colours on the set that make it look washed out. I will get the owner to have a look before I send it back.

[kc8adu]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

did you put the diffuser and polariser sheets back in in the exact order and orientation they came out?
that can cause odd symptoms.

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

The VES315 etc panels look terrible. They do the gamma correction on the main board instead of at the panel level so you get loads of banding which makes everything look a lot like an oil painting.

You can change the dim setting under the Picture menu, backlight MAX is not that bright though. Nothing you can do it is optimised to be as cheap as they can get away with. Honestly I would leave it at MIN to try and preserve backlight lifetime.

Exactly what I said to the owner keep the brightness low help save the life of those crappy leds. You are right as well it looks like an oil painting lol never seen a tv that looks so hideous in my life I dont know how people can stand to watch it also the sound quality is also horrible sounds scratchy and squeaky when ever bass is played, yet people will still swear that this junk has a good picture and sound quality. As you said you try to tell them not to buy it that its a pos but they do and dont listen, ohh well gives us technicians a tv to repair when they fail.

[tom66]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

The VES315 etc panels look terrible. They do the gamma correction on the main board instead of at the panel level so you get loads of banding which makes everything look a lot like an oil painting.

You can change the dim setting under the Picture menu, backlight MAX is not that bright though. Nothing you can do it is optimised to be as cheap as they can get away with. Honestly I would leave it at MIN to try and preserve backlight lifetime.

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Well just repaired this set used a 3w zener at 90ma tv turns on and works now. However the picture looks horrible almost washed out like its too bright but the leds do dim on start up guess its just because the lcd is crap because its a Vestel panel looks like a blurry painting the colours fade depending on what angle you view the set im too used of my pioneer kuro. I guess that this is a case of you get what you pay for, pay £80 for a set this cheap its going to last 6 months and look like crap so renting a tv for £14 a month not worth it. Charged £20 for repair hopefuly get a few more months life out of it just goes to show how cheap and unreliable products are getting nower days.

[freakaftr8]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

I just ran into a 2012 samsung. Same problem with these cheaply made 3 strip backlight systems. Edge lit seem much more reliable. This design appears to be inherited by oncorp. A. Chinese design. The backlight strips are inadequate for efficent cooling and eventually overheat and blowout leds.

[stj]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

looks pretty simple.
first, work out the size of the led's

then order a bunch of different ones from rapid.
http://www.rapidonline.com/Electroni...ace-Mount-LEDs

try them until you get one that gives the right brightness and colour.

you can change them with hot air - dont overdo the temperature or you will damage the lense.

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Thats 1 bad led out of the 200 in that panel, and how many of those panels non't have a problem. if that 1 led was replaced the rest of the led's might out last the rest of the tv.

Unfortunately I highly doubt that, I recon that after I repair this it will be another month or 2 before its out again designed to fail.

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Just got to find the type I need and corrected my comment I put 100v and 3w lol doh, I will see what I need tomorrow as the tv is at my unit.

[tom66]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

They would have to be rated at the LED forward voltage and power dissipation at Vf x I, where I is the LED current (around 20-100mA) and Vf is the forward voltage (around 3-4V).

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Yeah im looking at what zeners to use thinking 100ma 2-3v just checking what voltage the booster on this works at normally 70-90v @4 a but this is different voltage and current.

[tom66]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

The problem is while LEDs have a good overall lifespan exceeding 50,000 hours the early failure rate is quite high and if one single LED fails, the whole TV is usually unusable.

If the TV would operate with several LEDs out, there would not be a problem. There already exist antifusible zener devices which will short out failed LEDs allowing the rest of the set to continue operating with a minor drop in picture brightness. These would cost a matter of pence per LED to add to these sets yet manufacturers do not do this because it is not in their interest to increase lifetimes.

[R_J]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Thats 1 bad led out of the 200 in that panel, and how many of those panels non't have a problem. if that 1 led was replaced the rest of the led's might out last the rest of the tv.

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Here you go chaps, photos show the chassis of the tv which is pink plastic and one of the burnt up led diodes as you can see the glass on it has shattered you can see that the others still have their yellow glass on and its not like its in the middle of the strip which normally is the hottest part but I have a large suspicion its because of heat.

[tom66]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

This is pretty typical. If the LEDs don't go the panel will. The power levels are low enough now that power supplies are cheap enough to build reliably - there's little saving to be made there now. Failures come in the complex areas to save money on: panel, LEDs, flash memory, soldering under CPU etc.

[stj]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

conversion kits are fine,

the problem is the led tv's dont use enough leds, they just overdrive them to save money.
the kits stack the leds end2end - they use so many that you dont need to overdrive them.

[flocko]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Bulb are thing that you plant in the ground ? lamps are the things that light up. one of the first things that I was picked up on when I was a young lad in collage some 53 years ago , but I do think we are just seeing the beginning of these LED lamp faults with a lot more to follow Flocko

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

I will get you some today Stj, they might not be uploaded until later because I dont have wifi at my unit yet.

[stj]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Reecey, got any foto's of the led and surrounding area?

[ReeceyBurger123]

Re: Earliest Led Tv Backlight Failure Yet Please Read.

Wow wander how old that set is ???