Astounding Failure of Blue LED strings

[LORisAwesome]

Hi

 

Well, I fianlly got the strings of my Mega tree yesterday.  I know April is late, I've been waiting for better weather.

 

I use four colors in my display - Red, Green, White, and Blue.  The strings are bundled together into super strings with one of each color to a bundle.  The Mega tree has 48 bundles on it.  So there are 48 strings of each color.

 

As I took each bundle off, I tested each color before I put them in the storage tubs.  When I was finished I had 22 bundles with bad blue strings.  It got so bad, that I started testing the blue string in each bundle first.  I did not find any bad strings in the other colors.  I didn't test any of the other colors once I found a bad strings though, so there could be other colors that are bad too. 

 

These strings are 70 Ct LED full wave strings.  There is a small plastic oblong piece between the male plug and the first bulb, another in the middle, and another at the end between the last bulb and the female plug.  I'm thinking the plastic lump is a bridge rectifier, but, I don't know for sure.

 

On the majority of the strings the first half (closest to the male plug worked fine), with the other half having the problem.  There were a few that were the reverse.  There were some where half of the string would flash while the other was on steady.  I would suspect a poorly seated fuse if the entire string flashed. 

 

I've had LED strings go bad in the past, but, never to this extent.  This is almost half of the blue strings on my mega tree that had problems.  Even in the past, it seems that the blue strings failed more than the other colors.  At $15 a string this is very discouraging.

 

I did not buy these strings all at the same time, but over a couple of years.  I bought enough the first year to fully populate the tree.  I bought more the next year for spares.  I replaced some before I put the display up last fall.  I'm hoping that I got a bad batch of blue somehow and this is the last of it.

 

I guess I'm going to give my LED keeper a workout over the summer trying to fix these strings.

 

I'm curious to know if anyone else has experience failures like this?

 

I'm also wondering about the plastic lump.  Sometimes it seems that wiggling the lump would cause the string to flash.  Does the lump go bad?

 

Thanks

 

Jerry

 

 

[indi]

I had a section of my blue lights go out on a tree trunk that I wrapped. First section is fine and next is bad and the last section is good. I think my string has 3 of those lumps. I think they are at each section. Don't know if I can salvage them or just keep them for spare bulbs. I love the blue LED's, but I my not use them in my future shows. Can't keep buying new strings every year to replace. I'll never gain ground that way. May have to switch and go to dumb RGB's.

[TGabriel]

I believe this has been brought up before in another post about blue string failure.

[Dennis Cherry]

Yes, some blue LED strings are having excessive failures. This is not a saying all Blue LED's strings are bad, but seems the quality of whoever had these string made did have a quality problem.

 

I myself had about 30 strings of Blue LED strings given to me from a local dealer and all I did was keep repairing them, Fixed a string and plugged it in and after a while it would have have another failure(s) somewhere on the string.

 

Now being very stubborn, I had to try to find out why and how to fix it. Finally after much testing and verification I can say my strings where being over powered and drawing way too much current for the BLUE LED's used on these light strings.  

 

What may be the main cause is we demand brighter lights and the manufactures are pushing the envelope on what Blue LED's can handle.

 

I do have a fix and will be writing up my findings soon.

 

I do understand LED theory.

[LORisAwesome]

Yes, some blue LED strings are having excessive failures. This is not a saying all Blue LED's strings are bad, but seems the quality of whoever had these string made did have a quality problem.

 

I myself had about 30 strings of Blue LED strings given to me from a local dealer and all I did was keep repairing them, Fixed a string and plugged it in and after a while it would have have another failure(s) somewhere on the string.

 

Now being very stubborn, I had to try to find out why and how to fix it. Finally after much testing and verification I can say my strings where being over powered and drawing way too much current for the BLUE LED's used on these light strings.  

 

What may be the main cause is we demand brighter lights and the manufactures are pushing the envelope on what Blue LED's can handle.

 

I do have a fix and will be writing up my findings soon.

 

I do understand LED theory.

That would be greatly appreciated.  It will be a lot of work fixing this, even if I just replace the bad strings with new, I still have to seperate the bundles and then re-do the bundle.

 

Oddly enough, I used blue strings from the same supplier on the roof and had no failures of blue and only 1 red string that was bad out of 32 bundles.  These strings are newer than the mega tree strings though.   The roof strings were not used prior to the 2012 Christmas season.

 

Jerry

[Dennis Cherry]

This Blue LED problem may only be associated with a certain year, I believe it is 2010 production but not 100% sure.

 

Not all 2010? Blue LED's are defective.

[SteveMaris]

I would agree on the overpowering causing early failures. I have half wave big box store (target phillips brand) strings going on 5 yrs. without a single blue bulb going out. (over 300 strings)

[TGabriel]

One reason I have all my controller set at 90% intensity all the time.

[Max-Paul]

One thing I notice you said is that wiggling the wires near what we call wire warts, causes the lights to blink. I suspect those cases the wires got pulled on some and might have caused some wire breaks. Or the wires wiggled from the winds. Are most of these wiggle points near the middle wart or blob? Supper strings are great to help keep things straight and by bundling them it cuts down on the work setting up and tearing down. But it does add some weight to the wires. I used a small vinyl aircraft cable and zip tied to that cable. I made a loop that went onto the hook with this cable then at the bottom of the loop I attached the super string. Trying to keep the wires from making a tight sharp bend.

 

Now it is also possible that some of your failures can be as Dennis Cherry points out. And I do like TGabrel, except I max out at 50%. I dont really see much increase it lums between 50 and 100%. Stupid LED string factories pushing the limit.

[SteveMaris]

The candle that burns the brightest is the first to go out. 

[LORisAwesome]

One thing I notice you said is that wiggling the wires near what we call wire warts, causes the lights to blink. I suspect those cases the wires got pulled on some and might have caused some wire breaks. Or the wires wiggled from the winds. Are most of these wiggle points near the middle wart or blob? Supper strings are great to help keep things straight and by bundling them it cuts down on the work setting up and tearing down. But it does add some weight to the wires. I used a small vinyl aircraft cable and zip tied to that cable. I made a loop that went onto the hook with this cable then at the bottom of the loop I attached the super string. Trying to keep the wires from making a tight sharp bend.

 

Now it is also possible that some of your failures can be as Dennis Cherry points out. And I do like TGabrel, except I max out at 50%. I dont really see much increase it lums between 50 and 100%. Stupid LED string factories pushing the limit.

I was wiggling the wire wart near the male plug.  The end with the sharp bend is near the female plug.

 

I dunno, maybe that is why the half farthest from the male plug seems to be failing more....  The other colors are done the same way, and they didn't seem to fail.   I didn't check all the colors in a bundle once I had found a bad string, there could be other colors that failed too, but I doubt they failed as badly as the blue did.  

 

I also thought that bending it in this way would keep the female end pointed down so rain water would run off -- instead of into the female plug.

 

My mega strings that I use on the roof do not have any bends in them.  These strings run from the peak down to the gutter, and the female end is near the gutter.  I didn't make the bend in these to keep the female end pointed downhill.  I had only 1 bad string on the roof mega strings.

 

I like the idea of setting the max intensity on the controllers to less than 100%.  I wish I had known about the possibility of overloading the LED's earlier.  I will also consider re-stringing the mega strings with cable.  I have to fix almost half of them anyway...

 

Jerry

[iresq]

I have experienced very high rates of blue failures and have posted same. It's very frustrating but I think all my blues have been replaced in last 2 years so fingers crossed.

[David Rise]

I had an unusually high failure rate this past season with the Blue and Green strings.  Most of my LED's are 2yrs old now. All pro grade. I bought the LED light keeper pro and fixed them all.  I think it was Earle that said that lowering the power on the controller to 80% worked for him. I've set all of mine now, so hopefully I won't have as many failures this year.

 

We'll see.   But definitely buy the LED light keeper.  It works like a champ. Sacrificed one string of blue and one of green, but well worth it.

[systemdm]

Are ya'll setting the intensity in each sequence or in the controller? If in the controller, how are you doing this.

Thanks

D-Ray

Edited April 13, 2013 by systemdm

[jimswinder]

yep me too...

 

my thread about mine:

 

http://forums.lightorama.com/index.php?/topic/26080-high-failure-rate-of-blue-c7-leds/?hl=failure

[Steven]

I have an old 24-inch LED mini-tree I bought in 2008.  I had to repair it last year because several of the blue LEDs had failed. The other colors were working fine.

 

I also have one of these binary clocks at the office:

The "8" bit on the seconds is not working. I suspect an LED failure.

[Max-Paul]

Must have missed you saying it was at the wart nearest to the male plug. Looks like I am lucky to not have any blue strings in my display.  Just some of those C9 retros. Which I have had several in the past year suck some water into the sections with the LEDs. Good luck Jerry and anyone else having troubles with them.

[TGabriel]

Are ya'll setting the intensity in each sequence or in the controller? If in the controller, how are you doing this.

Thanks

D-Ray

I do mine at the controller.

It on page 442 in the LOR3 help manual. At lest the version I have.

 

Thomas

[EARLE W. TALLEY]

To change the output intensity you must hook the controller to the Hardware Utility program, after the controller is seen, go to configure (bottom of page), then set the intensity range to what max you want (86% is the lowest), then make sure that you update the unit ( over to the right) it will tell you that the unit was updated.

Even though I brought this up a while back there were people that wanted proof and others said I was nuts, I still think this works because I have a far less failure rate then I had before.

Hope this works for you, I would like to see LOR change it to 75% because there is very little change in the brightness of LEDs above 75%.

Earle

[systemdm]

Thanks Earle....