Anyone else have leds burning themselves out, or leds that are too yellow?

[NeedsMoreFlux]

I bought some leds off eBay, which the seller said were for this tv.

After changing them some of them would burn themselves out by developing a dark brown spot in the center of the led that would grow with time. the ones that didn't burn out were a bit more yellow.

Anyone else have this problem, or is it just my doing it wrong? Maybe too high temp?

I heated the backside of the led board. Used plenty of flux and fresh solder. I ran my cheap yihua at about 340-360degrees. And it only took me less than ten seconds to place most leds.

It did take a pretty long time to heat it up enough to melt the solder by heating the back side of the board. But I didn't want to blast the silicone inside the led.

[budm]

Re: Anyone else have leds burning themselves out, or leds that are too yellow?

Yea, what are the specs. of the LED?
Is the original is 3V or 6V LED?

[NeedsMoreFlux]

Re: Anyone else have leds burning themselves out, or leds that are too yellow?

I assume they are 6 volt less, because the boards have about 30 volts going to 8 leds. So they run at about 4.25 volts.

I asked the seller on eBay if he had gotten any messages regarding their failure rate. He suggested I was getting them too hot/too long.

What do you think about my install temps/heating the back of the board?

[diif]

Re: Anyone else have leds burning themselves out, or leds that are too yellow?

Yes, quite a few of the LEDs from Ali/ebay are not as cool as the original and have a slight yellow tinge.
I replaced an edge lit LED recently in a Panasonic. If you knew where to look with the TV showing a white background it was detectable but was not noticed normally.

Hotplate not hot air here.

[augiedoggy]

Re: Anyone else have leds burning themselves out, or leds that are too yellow?

I use a smd rework heat gun and heat from the back of the strip, that said Ive had a number of these sets come right back to me months later because once an led fails , if it shorts closed it increases voltage to all the rest in the series and although they worked fine when I replaced the bad ones , The damage was done it seems and they fail shortly after even with the backlighting set down.

Its gotten to the point where I wont warranty them unless im buying all new led strips.

so far the ebay leds have held up fine for me although I did buy some 6v ones supposedly exact matches for a 32" LG set I repaired and the polarity of all the led was reversed... set just failed again a few days ago after 1 month use and I replaced ALL the leds. (I HATE LG LED sets.) have like 5 of the same 47" model sitting in the garage all with the same led failure.

[budm]

Re: Anyone else have leds burning themselves out, or leds that are too yellow?

I assume they are 6 volt less, because the boards have about 30 volts going to 8 leds. So they run at about 4.25 volts.

I asked the seller on eBay if he had gotten any messages regarding their failure rate. He suggested I was getting them too hot/too long.

What do you think about my install temps/heating the back of the board?

30V between the Anode of the first LED and the Cathode of the last LED in the string or 30V with ref to GND?
You cannot assume if it is 3V LED or 6V LED with out making the measurement of the Vf of the LED. The seller cannot provide the spec?