having problems with ray woo's pixel nodes

[jxnms]

My most recent order from Ray for pixel nodes of the 650 pixel nodes I purchased 80 + % are bad. Has anyone else had this problem or know a fix. There seems to be something loose in them as you can squeeze them and the pixel will come on work for a few min then goes out again. When it goes out it cause all down stream pixels to turn white and flicker. As soon as I get one working another goes out. Tried everything I can think of. Still trying to get Ray. First time I have ever had problems with Rays stuff and have some of the same pixel nodes from 6 months ago work fine. Here is the style nodes I have


http://www.aliexpress.com/store/product/DC12V-WS2811-chip-full-color-led-smart-pixel-node-100pcs-a-string-with-all-black-cable/701799_785233760.html


also running in test mode on j1sys ecg-p2






thanks,


John

 

[harrison0550]

Oh no! DougD is having that same exact problem with pixels from Ray with the same black wiring. His are the bullet style though. I wonder if Ray had a large run of those with the black wire that were not made correctly. .

 

[ԆцряєсϮ]

I have 1400 of those same pixels.
Out of 1400 I had 10 that were faulty or DOA.
Although the quality seemed a bit poor compared to some I got earlier in the year (coloured wire).
A lot of the pixels were misformed ie. some werent round or had points on the lens, obviously some moulding issues
and a lot of them had sharp epoxy spikes around the cable entries, I kept sticking them into my fingers Other than that theyre all working OK

 

[jediknight2]

OK...are you saying 80% of your STRINGS have problems or 80% of the PIXELS have problems...keep in mind just because 50 out of a string of 100 are OFF..doesn't mean the pixels are bad...it can be ONE pixel causing it. I remember last year when I bought my first 700 pixels and had issues and was FREAKIN out...dead pixels are a way of life in RGB...

 

[slaska7629]

I have the same problem with the color wire version I got this year. Good thing my soder skills have improved lol

 

[dougd]

Here is quote from another forum.


Is it the whole string? Going white would be an extreme failure mode. [/size]When you power up a string without any signal input they normally flash white then go dark as they reset so either the output register blew with all "1"s or the output drivers shorted. If the output drivers shorted out then the LEDs would be extremely bright much more than normal plus they would likely start burning up the LED due to over current. The IC case is so tightly molded it's extremely unlikely that water could get to the silicon dice to cause a failure before the constant current drivers. Since the output drivers are low impedance a little moisture would not like cause an all white problem. If the moisture got to the input which is a high impedance signal I would expect flickering or a total loss of signal in which case the WS2811 will output the last data it received. Here is what I would suggest, disconnect the data wire and then power them up. I do this with the E682 just by disconnecting the data and then plugging the pixel string in while the controller is running a local test or a test from xLights. If the pixels come on full white then they are blown. If they flash white then go dark they at least the output register, drivers and reset circuit sections of the chip is still working. Some of these pixels are once that really need to be opened after being wet. Some of the ones being sent in for dissection should be put into just enough water to cover the parts of the pixels that surround the wires and the LEDs.BTW, I'm going to talk to some of the injection plastics manufactures, once my show is running, about different plastics and how they adhere to different wire insulations and the resins use for the LEDs. I'm really to the point that I think if there is a water ingress issue with the TCs its due to the plastic body not molding tightly adhering to the wires. Another point is that Ray was supposed to be conformal coating the pixels PCBs before potting. I need to ask him about that when it comes to the TC's The conformal coating is the last line of defense if any moisture does get past the case to wire/LED boundary. That coating should basically stop any moisture from getting to the components.Before looking at changing to a 5050 LED or making changes to the regulators or other logic we must determine if water is getting into the case and if it is solve that problem.

 

[dougd]

What i am seeing is at least 50% of my strings have some amount of bad pixels in them. How many bad pixels are in each string I am not sure. I tried to fix one string and after 3 pixels quit.

 

[jediknight2]

That falls in line with what I had last year and this year

 

[smeighan]

What i am seeing is at least 50% of my strings have some amount of bad pixels in them. How many bad pixels are in each string I am not sure. I tried to fix one string and after 3 pixels quit.

i have had 4 out of 20 flex strips, ws2811 12v have a problem. all 4 were a bad solder connection at the resistor. I could see a micro line on it. I cut back the flex, reflux and flowed the resistor, all 4 now work. I then used silicon rtv to reseal the cut section.


i also do not believe this has anything to do with ray but with his suppliers. ray does not burn in these strings (He must ship 1000's of them). i wish the factories had a simple vibration test if they test them at all. last year i had 1 bad string out of 40.

 

[riri7707]

The most problem with the Chineese suplliers is the quality control.
These is NO control quality...
So somewhere it's mandatory to check and repair the small problems...
Most of them are soldering problems....

But don't forget, we buy the quality reflected by the money we paid for.
This is not magic...

So always take more pixels than necessary to get some spares...

From 1600 pixels, I had 18 with bad soldering, so I fixed that.

This is also part of DIY side...

Other way, control quality will affect 10 cents min or more for each pixel for testing : normal...

 

[riri7707]

Another small thing,
Regarding moisture on connections, this is not due to a waterprofing problem with manufacturers, this is just a natural issue with the temperature conditions when the devices are build.

The air always have water on it and Under some specific condition the water appears.

As you always have some air Inside the devices, even if you waterproof correctly all, the fact going from hot to cold weather conditions will generate naturally water Inside the led modules, strings, etc.... This is why moisture appears on connections PCB and finnally generates a lot of problems on the displays.

Most of the external enclosures for lighting have always 2 small holes for natural air circulation to prevent moisture. But this cannot be applied to our small light devices.

As this is not a 100% short-circuit, but involves hazardous resistance between connections, the faillures are not always the same, once daylight SUN appears, the faillure desapears, but the next night with humidity the problem will appear again and so on. So enough difficult to isolate and find the faulty device.

The only way to prevent that is to apply resin (transparent) for example over the electronics PCB and connections.
Then you have all chances from your side to have your devices safe for long years without any moisture...

The other option for small strings with LED is to fully fill with resin all led and pcb to avoid any air Inside...

Silicon is not so usefull than it appears as it reacts also to hot and cold conditions, so at end, the waterproofing desapears after a short period and the water and humidity can again enter in the small holes...