When a pixel dies...

nutz4lights

Full time elf
Joined
Dec 12, 2012
Messages
305
Location
Melbourne, Florida
So... I have reached another one of those moments where I don't understand something. I searched the 101 lighting manual and didn't come up with anything. I watched the RGB Basics #2 video and that talks about how to fix dead pixels.

I have six x 50 pixel 2811 strings running vertically up and down a palm tree trunk. They are linked together so that they are using three outputs of a P12R. Each string was tested in my garage prior to putting them up on the palm tree. They have the waterproof pigtails on on both ends of the string. I am injecting power at pixel 100 on each of the three pixel string pairs.

I went to hook up the P12R out in the yard today and when hooking up one of the power injection connections, I heard a slightly click (like an arc). Now, pixels 51 through 100 are not lighting on that string set. Pixels 1 through 50 light just fine. The thing that is confusing to me is... I thought when a pixel died, every pixel AFTER that pixel shouldn't light. The odd thing here is... I was connecting the injection connection to pixel number 100 when I heard the click... are you telling me that pixel number 51 (at the top of the palm tree 20 feet up in the air) is dead at this point and not allowing the data to reach pixels 52 through 100? Am I understanding that correctly? That seems almost unbelievable to me.

I took a volt meter out there and I have voltage at pixel 100 just from the pixel 1 connection (obviously without the injection cable connected) so it must be a data issue right?

I appreciate the input.

Thanks!
 

DeeJai

Is that Magic Smoke?!?
Joined
Oct 18, 2011
Messages
1,008
Location
No longer in Radelaide
well, if your getting power down the line, then yes it is more then likely a data issue,

Being that it stops after pixel 50, you have probably killed pixel 50 or 51.

I have been told, when in doubt, replace the pixel before and the first non working pixel.
See if that helps you.
 

nutz4lights

Full time elf
Joined
Dec 12, 2012
Messages
305
Location
Melbourne, Florida
That's what I'm figuring, I just don't get how I could kill pixel 51 when I was connecting to pixel 100 over 6-7 meters away... but I guess that is electricity for you... Luckily this is just test mode and it is summer...
 

logandc99

Dedicated elf
Joined
Jul 13, 2012
Messages
1,153
Ok so I'm no expert and you probably have way more experience than me so this may be a silly suggestion but I have had similar things happen with only the first 50 pixels lighting only to find that problem was a configuration issue so only data was going to the first 50 pixels. When I ran my p12 on the test pattern mode, all 100 pixels lit which was a good hint that it was how I had configured the light output either in the P12 or LSP. Checking the settings I then found the config error, corrected and all pixels lit. Have you tested the string on the test pattern mode which tends to light up the whole string if its working?
Just a thought before you starting cutting up a set of pixels to try and replace one. Just sounds odd that it stopped right on pixel 50 that's all (as if that output from the P12 is only set to send data to 50 pixels or 150 channels).
 

jerrymac

Apprentice elf
Joined
Mar 29, 2011
Messages
72
Location
Quitman GA
I had kind of the same problem but it was due to my error . (5 volt pixels do NOT play well with 12 volts and 8 strings failed at various points). Aany way I had to narrow down which pixels were damaged. In some cases the pixel before the failure point had failed (chip was not passing data down the line. In some casess it was the first failed pixel that was completely blocking data. I started by cutting out the first failed pixel and connecting the rest of the string. If this resolved the issue that was the damaged pixel. If it did not I removed the pixel before and re-checked to see if this resolved the issue. A little bit of cut and jumper but I was finally able to resolve the bad pixels.
Short sugesstion. remove the first failed pixel and jumper the reset of the string, if no luck remove the pixel before the failure. Hopefully this will help find the failure point.
There may be a technical way to find the failre but this worked OK for me.
 

DeeJai

Is that Magic Smoke?!?
Joined
Oct 18, 2011
Messages
1,008
Location
No longer in Radelaide
yeah, logan raises a valid point, perhaps you havent set up 100 pixels in your p12 setup. just confirm that you have 100 pixels setup there else, you will stop at the 50 or whatever the value is.
 

nutz4lights

Full time elf
Joined
Dec 12, 2012
Messages
305
Location
Melbourne, Florida
Thanks guy. I will double check in the morning, but I'm 99.999% sure I have the pixel output at 100. Like I said, the strings were working fine off the P12R before I took them out to the tree to hook them up. What I may try to do tomorrow is free up the one non-functioning string and hook it up directly to the P12R to see if it lights... It is still bothering me that the 50th or 51st pixel died when I connected the injection power to the 100th pixel.
 

Beefer

Apprentice elf
Joined
Feb 19, 2012
Messages
55
Sounds like the title of a sad Christmas Lighting Carol, 'When a Pixel Dies" ;)
 

fasteddy

I have C.L.A.P
Global moderator
Joined
Apr 26, 2010
Messages
6,648
Location
Albion Park NSW
If you had disconnected or reconnected the pixels when the power was on then this will damage the first pixel in manay cases.

Same if you connect or disconnect the injection when the pixels are running can also cause this issue.
 

nutz4lights

Full time elf
Joined
Dec 12, 2012
Messages
305
Location
Melbourne, Florida
I bet you the power was on... I keep forgetting that the power is on at the string even when nothing is running... which is a huge switch from my days of conventional LED lights... @#$%@#$$

:D
 

rvenegas

Apprentice elf
Joined
Apr 9, 2013
Messages
60
Location
Orlando, FL. USA
Maybe i`m wrong but, it sounds like connections between pixel 50 and 51 were inverted, that will damage pixel 51 and maybe copule more after and maybe the "click" you heard was due the short circuit for power injecting at pixel 100 having a nice "meeting" with inverted electricity at pixel 51.
 

nutz4lights

Full time elf
Joined
Dec 12, 2012
Messages
305
Location
Melbourne, Florida
I can't wait to get this string down this weekend and check it out... I put the connectors on and I thought I did it right, but a short loss of focus could result in a mistake...
 

rvenegas

Apprentice elf
Joined
Apr 9, 2013
Messages
60
Location
Orlando, FL. USA
nutz4lights said:
I did it right, but a short loss of focus could result in a mistake...

You are so right, when I was assembling my matrix i made triple check with wire connections, at third check i found one string inverted. When i turn it on the first time, even after 3 round check i was a little bit nervous. So, mistakes happens. One advise, do as U.S. Marine Corps says "double tap shoot and then a grenade just to be sure"
 

nutz4lights

Full time elf
Joined
Dec 12, 2012
Messages
305
Location
Melbourne, Florida
So I finally got these lights down off the palm tree. I set them up in my garage on the floor, each of the six strings was tied to its own output from the P12R (the setup on the palm tree was three outputs with the 50 count strings linked to form a 100 count string on each output). Anyway, all six strings worked just fine and dandy.... SO... I went and attempted to measure the output voltage at the end of each string and found that the one string that was causing issue had the connector soldered on incorrectly by me... whoops... at least all the strings are working, I got lucky... so now I just have to snip off that one connector.

FYI. Thanks!
 

logandc99

Dedicated elf
Joined
Jul 13, 2012
Messages
1,153
Glad to hear you found the problem and didn't have to start cutting up your pixels.
 
Top