Only 7 of 16 pixels light up on Neopixel ring

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Phdrumlineka
 
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Only 7 of 16 pixels light up on Neopixel ring

Post by Phdrumlineka »

Hello, I recently received a 16 pixel neopixel ring. Over the weekend I got some leads soldered to it and when I got it up and running, only 7 of the 16 pixels will turn on. The ones that do turn on are from one before the labeled "Power 5v DC" towards the other v+ solder hole around to one before the data out solder hole. Is there anything I can do to fix it, or can it be replaced? I have attached a screenshot of a neopixel ring with the pixels I am referring to circled.
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NeoPixel_working_pixels.PNG
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adafruit_support_bill
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by adafruit_support_bill »

Post photos of the front & back of your ring, showing the soldering to the ring.

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Phdrumlineka
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by Phdrumlineka »

I have attached pictures of the front and the back. I did have trouble with the 5V on the front side and I hit those two pixels with the iron (My solder was a bit bigger then it needed to be.). But both of those pixels are in the group that are working. Sorry if the quality of the pictures is too bad for any detail. Looking forward to a response.
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Front of neopixel ring
Front of neopixel ring
Front.png (175.28 KiB) Viewed 890 times
Back of neopixel ring
Back of neopixel ring
back.png (132.65 KiB) Viewed 890 times

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adafruit_support_bill
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by adafruit_support_bill »

The signals on that chip flow in a counter-clockwise direction - starting from the pixel just above the "out" connection - the first pixel in the group that lights. (If you follow the traces on the back, you will see that the "in" connection is routed down to that pixel.

Moving counter-clockwise from the 5v connection, the output pin for the following pixel is right next to the 5v solder pad. Most likely what happened was some solder from the 5v pad bridged to the output pin. So while the next pixel does light up, the signal is not passed to the next pixel.

You have a bit more solder than necessary on most of those connections. This guide has some tips on fixing those:
http://learn.adafruit.com/adafruit-guid ... n-problems
.
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neopixel pinouts.PNG
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Phdrumlineka
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by Phdrumlineka »

I attempted some clean up work. and I am still getting the same results (only 7 pixels working). Here are some more pictures of the cleaned up soldering. The V+ soldering is where I suspect my problem is, but at this point I can't see what would be the offending area. Any further thoughts, or is this a now "broken" ring?
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Front_5V.PNG
Front_5V.PNG (852.53 KiB) Viewed 871 times
Back_DataOut_DataIn.PNG
Back_DataOut_DataIn.PNG (486.32 KiB) Viewed 871 times
5V_Back_Solder.PNG
5V_Back_Solder.PNG (411.41 KiB) Viewed 871 times

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adafruit_support_bill
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by adafruit_support_bill »

The solder joint looks much looks better now. But the damage may already be done. You can see traces of the solder bridge on the output pin of the next pixel. A 5v source applied to the output pin would stress the signal output transistor and it would probably not take too long for it to overheat and fail.

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Phdrumlineka
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by Phdrumlineka »

I appreciate you assistance! Would you say the best course of action is to embrace this loss, and purchase a new one? ( I already bought smaller solder, and got some good practice when trying to clean up this project.)

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adafruit_support_bill
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by adafruit_support_bill »

Damage in cases like these is typically limited to one or two pixels. You might be able to salvage 15/16ths of the ring by running a jumper from the output of the second-to-last lit pixel to the first unlit pixel. If nothing else, it will be good soldering practice.

If you contact [email protected] with a link to this thread we can offer you a discount on a replacement.

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Phdrumlineka
 
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Re: Only 7 of 16 pixels light up on Neopixel ring

Post by Phdrumlineka »

Thanks again for you help! I am going to get in contact with Support. I will also look into trying to jump that potentially fried pixel.

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