What happened to my pixels?

vincerules

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I have a matrix that is 14 strings of 2812b 30 pixels per meter 3 meter long strips.
I am running it off a P2, 7 strings off each port.

The strings on port 1 are powered from the same power supply that powers the P2
The strings on port 2 are from a separate power supply
Both power supplies are the 5v/350w from Ray Wu.

I've had the first 7 strings (top half of the matrix) working for a few days now and today I finally got the second power supply wired up and connected it to the second set of pixels.

The second set didn't work, so I swapped the power connectors (i plugged the first set into the second power supply and the second set of pixels into the first power supply). Now the first set of pixels doesn't work either.

I used a spare pixel strip straight into the P2 and it works, so I'm thinking maybe I toasted the first pixel on each set of my matrix. I tested the end of the strips and am getting 5v so I know they are getting power.

Does this sound like something that could happen?
Was there something else I was supposed to do to use 2 power supplies with one P2?
 

kane

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You do need to ensure that the ground of both power supplies are connected (so you have a common ground, as the data signal requires this)

But in terms of your broken strips, it seems very unlucky to fry the first chip on all 14 strings, unless there was a wiring issue (ie, you fed 5v into the data line)

I'm assuming that you're running 7 strings in parallel off each output?
 

fasteddy

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You may have a plug that may have crossed over terminals, it definetly wouldnt be the first time with Rays plugs

Are you plugging and unplugging the pixels whilst running and power on, this is a big no no and can cause the first pixel to die
 

vincerules

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They are all connected in series. I didn't have the grounds connected.

One other thing I noticed, on the second power supply I switched the 115/230 switch to 115 and after the problem came up I noticed the first power supply was set to 230. but the lights had been working on that setting for the past few days.
 

kane

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oh hang on, it's a matrix, so you wouldn't be running 7 strings in parallel, you're obviously running in serial... But then, why are you thinking you've damaged the first pixel in all 14 strings? Perhaps you're injected power at the start of each string.. In which case, I'm thinking you may have had a wiring issue with power injection??
 

kane

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vincerules said:
They are all connected in series. I didn't have the grounds connected.

One other thing I noticed, on the second power supply I switched the 115/230 switch to 115 and after the problem came up I noticed the first power supply was set to 230. but the lights had been working on that setting for the past few days.
You'll definitely want to have the grounds connected.

I wouldn't think that the 115/230 switch would make a difference - if you test the output and it's at 5V, you should be fine.


Are you able to isolate one of the strips (say, the 2nd one), and connect this directly to the P2?
 

fasteddy

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vincerules said:
They are all connected in series. I didn't have the grounds connected.

One other thing I noticed, on the second power supply I switched the 115/230 switch to 115 and after the problem came up I noticed the first power supply was set to 230. but the lights had been working on that setting for the past few days.
It will still work with 100v and set to 230v but with greatly reduced capacity, now if it was set to 110v and connected to 230v then it would go bang.

But not having the grounds tied together will definetly cause issues
 

vincerules

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I'm thinking I just damaged the first pixel on the first strip of each port not on all 14 strings.

I plan on trying the second string in the series tomorrow. Bath time for the kids getting in the way of my troubleshooting


Sounds like it could be the ground thing that I screwed up
 
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