Conventional Fixtures LED FLICKER WITHIN LIGHTING FIXTUTRE?

[michilson]

Hey guys I want to throw this out here ans see what offers you all might have to help.

I have purchased RGB Par 38 Lights from the manufacture in China ( The price was right)

They are a copy of the Chauvet LED SPLASH 86b (Currently DISCONTINUED SINCE 2012)

Here's my questions for you all:

When I purchased these lights everything workd fine!

Now after a year and about (30 hrs) of use the LED's are starting to flicker.



When I select Blue Several of the Blue LED's (Flicker) like a row of 4-6 & some dont event turn on?

Green is the Same Groups of 4 -6 Flicker or dont turn on

Red doesnt seem to have this issue as of yet.

Please note not all LED's of the Color selected flicker most stay solid but up to 10 - 12 flicker (Causing a strobing apperence) when a solid color should be shown. Any suggestions would be great! I know that purchasing theses directly was a misstake please try to help provide a solution other than get new lights!

Thanks!

 

[PeteEngel]

Not sure there is anything you CAN do. Any possible chance of replacing the LED's that will match are probably gone since the Knock-Offs use the cheapest LED's they can find with little or no thought to future protection or compatability. Looks like you are going to have to chalk this up to experience unless someone here has replacement LED's. I'm presuming you have contacted the manufacturer to see if these are still under warranty or if they have replacement parts. Just because you purchased these units from the Manufacturer as opposed through a dealer doesn't mean you are without warranty. If the company is still in business (that is a big question) then they should have some support capability.

Good Luck.

 

[sk8rsdad]

My guess is there are plenty of cold solder joints in the fixtures. I had the same issue with some first generation Blizzard Pucks. If you have access to a reflow oven you could pull the boards out and run them through. Otherwise, it's a tedious day with a soldering iron reheating and reflowing all the joints.

 

[michilson]

I'm not opposed to trying that I found that one of the feed wires had fallen off in transit as well. If I take on the the LED's out is there a way to test it to figure out what I could replace it with? (I.E. Replacing every LED on the fixture with new bulbs? Better quailty LEDS?

 

[Esoteric]

I'm not opposed to trying that I found that one of the feed wires had fallen off in transit as well. If I take on the the LED's out is there a way to test it to figure out what I could replace it with? (I.E. Replacing every LED on the fixture with new bulbs? Better quailty LEDS?

This is why I always recommend that if you are going to by Chinese units, either by 20% worth of spares or buy from a Distributor in America.

 

[techieman33]

I'm not opposed to trying that I found that one of the feed wires had fallen off in transit as well. If I take on the the LED's out is there a way to test it to figure out what I could replace it with? (I.E. Replacing every LED on the fixture with new bulbs? Better quailty LEDS?

When you can buy a new one for $30 you really need to consider that cost vs. the cost of your time and the parts you'll buy to fix it.

 

[michilson]

I bought them new for $30 at the time the units here in the states where almost 3 times the cost. I do understand the quailty issue. However this doesnt help to fix the problems I am currently seeing!

 

[Esoteric]

That is the point. Units that cheap aren't meant to be fixed they are meant to be trashed and replaced. If you need 4 of them you should order 6 or 5 at the minimum, if you need 8 you should order 12 or at least 10 at the minimum.

 

[michilson]

Well getting back to the topic is the connection between the leads of the LED's and the circuit board the cause? or is the LED the issue? might beef up the supply wires to the circuit board as well!

Thanks?

If I pull the LED's off the Circuit board is there a way to measure them to find replacements? or a calculation i can do to figure out what type of LED they are?

 

[sk8rsdad]

All of the individual components are likely fine. LEDs shouldn't need replacing. The issue is likely the workmanship of the solder joints. They can be fixed without removing anything. My guess, based on your questions, is this is not something you would normally do. Esoteric's advice may be more appropriate than my DIY fix.

 

[Esoteric]

All of the individual components are likely fine. LEDs shouldn't need replacing. The issue is likely the workmanship of the solder joints. They can be fixed without removing anything. My guess, based on your questions, is this is not something you would normally do. Esoteric's advice may be more appropriate than my DIY fix.

Having been on the inside of more than a few Chinese fixtures, those joints are VERY touchy. If you are not an expert solderer, I would recommend not to waste your time.

 

[JD]

Lets say there is a chain of 5 or 6 that are out. With that color on, take your fingertip and lightly push each dead one in a circular motion. If it's a bad joint, you may find the chain comes to life while you are pushing on the one that is the offender.

Like others have said, bad joints are a big problem on the cheaper fixtures.

 

[AEGProduction]

I have had LED's that have gone bad in some fixtures. It was usually a single LED that took out the rest of the chain. They were definitely a "made in china" light, but they were sold through a small US distributor. However it was definitely not worth the shipping to be sending a light back and forth every time one went out. So I decided to fix it myself.

I noticed that the culprit was almost always a red LED that had gone bad. What I found extremely interesting though, was that it was not the solder joints (not saying this isn't a problem with chinese fixtures).

(I do not recommend this practice)
Upon replacing the LED, I had the unit open with the LED board out. I plugged in the unit to find the bad LED, and left it running while i was removing it (Probably a horrible idea). I noticed that when I heated up the joints to the LED, the LED would pop on and it would magically work. I thought at first I just fixed a bad joint. So I removed all the solder on the pad and LED, replaced it with fresh solder and started re-assembly. After I had gotten everything back together, I noted the same string out again..... Repeated the process, only I had waited a little before re-assembly. Same problem, after about 45 seconds or so, the LED would open, and the string was out again....

I found that heating the LED was the only way to get it to work again. I have only seen this problem with this one manufacturer though (I have worked on LED PARs from several). Really odd. I replaced the LED with a new one (bought thousands of diodes for electronic projects when I was in school). The color surprisingly matched, and the strings that I have replaced have not needed any work since. I have theories as to why this is happening, however no technical data to really back any of that up.

As for the flickering. The few times the pars that I have fixed have this issue is usually a result of a faulty cap. In my cases it was clear which cap was faulty as it was either completely removed from the board or puffy and leaking.

 

[JD]

I have theories as to why this is happening, however no technical data to really back any of that up.

What happens inside is not a mystery, it is the bane of existence for all solid state devices that generate heat. The three components found in all solid state devices are:
1) The subtract/junction (This is the actual IC or junction device)
2) The lead/pin (This is the external leads or pins that you connect to.)
3) The jumper (Usually a fine piece of gold or platinum wire.)

The jumpers are spot-welded to the chip and then spot-welded to the input lead. Unfortunately, all things do not expand and contract at the same rate. At some point, the spot-weld breaks free of the chip. The bigger the thermal cycle, the sooner the failure. Once it has broken free, it may still be in contact with the chip in certain temperature ranges. This is why heating and/or cooling a device is a standard diagnostic practice. It is also why some devices (like an LED) may turn into a blinker light!

Now, back to the LED failure. If this is the mode of failure it is very simple to track down the failed device in the chain. Just look for one that has an unusually large voltage drop across it. Another way is to take a 100 to 200 ohm resistor and bend it so the leads are about the same width as the LED pads. Press it into the solder pads of each LED, one at a time. When the rest of the chain lights, the one you are bypassing it the bad one. Some people simply short each LED with a screwdriver tip to see if the rest of the chain lights. This can damage the driver circuit, which is usually very marginal on the cheap ones. Best to use a resistor.

 

[AEGProduction]

That is, in a nutshell, exactly what I was thinking was going on, just couldn't prove it (didn't spend enough time researching).

I use the resistor "bridge" to diagnose the faults as well, found that one out the hard way HA!

 

[church]

strobing in LED fixtures is normally one or more capacitors in the switch mode powers supply that is failing. This is a common problem and is found in power supplies designed and manufactured in many countries. The problem is the wrong capacitor has been selected (Equivalent Series Resistance is too high and the temperature rating is too low) the ripple current due to the PWM approach for LED dimming cause the caps to run hot and begin to break down increasing the ESR which makes the capacitors run even hotter. The answer is to replace the capacitors with ones with a lower ESR and higher temperature rating. This may or may not be in within your knowledge range. The trick is knowing which capacitors to change and what to use as replacements. Note the cost for high performance capacitors can be a shock so you do not just want to replace every capacitor because it is unnecessay and expensive. There are a number of technical papers published in the professional engineering magazines on this topic.

This problem is also well documented for computer manufacturers and even HP has struggled with it.

Your best approach if you do not have the knowledge and skills yourself is to find someone who does who can help you out.