MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs are

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tmc1233
 
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MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs are

Post by tmc1233 »

Hello,

I carefully assembled this kit yesterday and have found that LED 1 flickers at a considerably lower rate than the others. LEDs 5 and 7 only display in white when warm—i.e. after soldering. As soon as they cool down, the green component goes out. It should be noted that some of the LEDs’ leads were bent when I received the kit. I have gone over entire board to look for solder bridges or bad joints—everything looks good. All flux has been cleaned off as well. Still, as soon as 5 and 7 hit room temperature they act up along with 1 flickering very slowly.

UPS may have been rough with the package...
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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by adafruit_support_carter »

Can you post another photo showing the soldering on the backside. With ambient light so the LEDs don't wash out the image.

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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by tmc1233 »

As requested, here is the back side of the circuit board. Thank you for any help you may provide.

~Todd
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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by adafruit_support_carter »

Are you running it with the code it shipped with? So that you can run this test:
https://learn.adafruit.com/minipov4-diy ... it/testing

Your soldering looks generally OK. Check the few things I've shown in the image below.
  • A = hard to tell, but maybe a little under soldered
  • B = fuzzy stuff, if it's something conducting could be shorting things
  • C = is there a solder short here?
soldering.jpg
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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by tmc1233 »

Thanks for looking at this. I have fixed the items that you pointed out, and a few others. Strangely, I have run into more issues! I’ll get this sorted out yet!

I have not introduced my own code into the module...
It was tough to see the self test, as it is so fast—it cycles in less than a second. I have checked all of the things that you have suggested, and a few more. LED 1 still seems to flicker at half the rate of the other LEDs. Now, LEDs 2, 4, and 5 are not displaying green. This has been verified by videoing the start up in slow motion. I have posted video here: https://youtu.be/ewV7Z319ceY

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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by tmc1233 »

Any further assistance would be appreciated.

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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by adafruit_support_carter »

Sorry for the delay. That video helps, thanks for that. For only the green channel to not be working on specific LEDs, it kind of indicates either a soldering issue on the green channel pins or something wrong with those pixels.

Can you post another photo showing the backside of the board after you've made the repairs.
It should be noted that some of the LEDs’ leads were bent when I received the kit.
Were any of them so badly bent that they were broken off, or even about to break off?

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tmc1233
 
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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by tmc1233 »

They were not broken off, but I wonder if there was internal damage. It seems odd that the LEDs only work when heated (expansion of metal across a tiny split?).

I have bought replacement LEDs and will check to see if they help.

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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by adafruit_support_carter »

They were not broken off, but I wonder if there was internal damage.
Maybe. I think these do have tiny wires inside that bring the external pins down to the actual LED dye. But why only green? Guess it could just be the luck of the draw.
I have bought replacement LEDs and will check to see if they help.
Awesome. That's going to be a bit of resoldering work, cool that you're up for it. Yes, please let me know what happens with this. Sorry this is being so problematic.

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Re: MiniPOV 4 Kit - DIY Full-Color POV and Light Some LEDs

Post by tmc1233 »

Wow, I just saw your reply after all these months. I am finally ready to use the MiniPOV and now this: viewtopic.php?f=11&t=141045

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