LPD8806 chips getting hot enough to burn skin

by nakedhoof on Mon Jun 18, 2012 10:28 am

Not only that, but my strip does not work correctly. Some LEDs light, and some do not. Nothing happens when I run any of the demo programs. I've checked the wiring and it is exactly like that in the tutorial.

I think it's defective. Most of the chips do not get hot. Since this strip was rather expensive, I'm not very happy.
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Re: LPD8806 chips getting hot enough to burn skin

by adafruit_support_bill on Mon Jun 18, 2012 10:48 am

Please post photos showing all your connections to the strip.
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Re: LPD8806 chips getting hot enough to burn skin

by nakedhoof on Mon Jun 18, 2012 11:12 am

Image

Before you ask, I have switched the white/blue wires, same result.

Red = +5v
Black = GND
White = DI
Blue = CI
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Re: LPD8806 chips getting hot enough to burn skin

by adafruit_support_bill on Mon Jun 18, 2012 11:27 am

Show us the connections to the strip itself. Make sure you are connecting to the input end of the strip.
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Re: LPD8806 chips getting hot enough to burn skin

by nakedhoof on Mon Jun 18, 2012 11:42 am

Image

Before you ask, I have switched the white/blue wires, same result.

Red = +5v
Black = GND
White = DI
Blue = CI

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Re: LPD8806 chips getting hot enough to burn skin

by adafruit on Mon Jun 18, 2012 11:52 am

You have a split-supply breadboard, which is causing the strips to not be powered correctly. connect the red wire powering the strip DIRECTLY to your +5V power supply

see for more details https://www.adafruit.com/products/443

what precise 5V power supply are you using?
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Re: LPD8806 chips getting hot enough to burn skin

by nakedhoof on Mon Jun 18, 2012 11:57 am

adafruit wrote:You have a split-supply breadboard, which is causing the strips to not be powered correctly. connect the red wire powering the strip DIRECTLY to your +5V power supply

see for more details https://www.adafruit.com/products/443

what precise 5V power supply are you using?


I'm sorry, but you're wrong: my breadboard has nothing to do with this. I connected the +5V supply directly to the red wire. Same thing.

I've been doing this for 35 years. I think I might know a thing or two. The supply is the Elenco XP-720, and I am using the fixed 5V 3A output.
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Re: LPD8806 chips getting hot enough to burn skin

by adafruit on Mon Jun 18, 2012 12:02 pm

nakedhoof wrote:
adafruit wrote:You have a split-supply breadboard, which is causing the strips to not be powered correctly. connect the red wire powering the strip DIRECTLY to your +5V power supply

see for more details https://www.adafruit.com/products/443

what precise 5V power supply are you using?


I'm sorry, but you're wrong: my breadboard has nothing to do with this. I connected the +5V supply directly to the red wire. Same thing.

I've been doing this for 35 years. I think I might know a thing or two. The supply is the Elenco XP-720, and I am using the fixed 5V 3A output.


OK lets remove the breadboard from the setup then - wire up the strip directly to the Arduino data lines and the power supply with a short (under 1 foot) cable.

Its great to hear you've been doing this for 35 years, so lets get the scope out and debug it! can you check the 5V line right at the strip input - whats the DC voltage and and AC ripple?
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Re: LPD8806 chips getting hot enough to burn skin

by nakedhoof on Mon Jun 18, 2012 1:38 pm

Sorry, but I get no thrills from debugging something I paid for that does not work, nor do I think that any support person on the planet should suggest it. The supply is fine, and several chips are getting hot enough to burn skin. I don't need an oscilloscope or anything else to tell me that there is something wrong, and that my power supply and hookup are to blame, when they are not.

A properly functioning chip will not overheat like this. End of story.

You just lost my business.
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Re: LPD8806 chips getting hot enough to burn skin

by adafruit on Mon Jun 18, 2012 1:49 pm

Hi there nakedhoof, all strips are tested before shipment from the factory and we've -never- heard of this problem in the years of selling LED strip so we think there could be something else that could be happening. Since we're not there with you, we were hoping you would help us debug the problem - a chip could be overheating for a few different reasons. Since as you said you have a lot of experience and expertise, you know many things could be happening. And we'll here to help you if you'll let us assist you.

Please remove the breadboard from the setup then - wire up the strip directly to the Arduino data lines and the power supply with a short (under 1 foot) cable.

If you're not willing to do this, you can send the strip back if you'd like and we can test it for you. You're also welcome to send it back for a full refund.

Thank you,
Adafruit support, Phil
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Re: LPD8806 chips getting hot enough to burn skin

by DigitalMethod on Mon Nov 12, 2012 9:59 am

Not sure if I should be piggy-backing this post, but I am experiencing a similar problem.

The problem I am having is that not all of the LEDs seem to be working and some of the chips between the segments get exceptionally hot. There don't appear to be any specific chips or LEDs acting up as it varies from power up to power up. The only thing that seems to be consistent is the first 12 or so LEDs are responsive - initially they just randomly flashed and changed colour, but this morning the LEDs were chasing colours when using the sample code. The second from last segment usually stays on with each LED set to some random colour. Sometimes the LEDs in the middle turn on, but they usually just stay white and not all LEDs would work. Occasionally some will flicker on and then off again.

I followed the tutorial on setting this up with an Arduino. I had to solder leads onto the input side of the strip. I triple checked the wiring, made sure the sample code was set to the correct number of LEDs, applied pressure to the chips all along the strip, switched the Arduino to the same power source as the strip, checked for any shorts or damaged connections (I didn't see any), but still the same problems. I am currently powering everything off of an ATX power supply and my probing reports a steady 5.15V. I have also removed my breadboard from the setup as the last post suggests and my connections, including the data line, are under 1 foot in length.

Thanks in advance.
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Re: LPD8806 chips getting hot enough to burn skin

by adafruit_support_rick on Mon Nov 12, 2012 10:25 am

Please post detailed pictures of your wiring and soldering, and we'll have a look!
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Re: LPD8806 chips getting hot enough to burn skin

by DigitalMethod on Mon Nov 12, 2012 8:31 pm

Hopefully these will help troubleshoot the problem. The breadboard terminals are connected the the 5V rail of the ATX power supply. The 12V leads are not connected and are taped off.
Attachments
DSC00499.jpg
Side shot that hopefully illustrates the pin out.
DSC00499.jpg (325.49 KiB) Viewed 834 times
DSC00496.jpg
Top down of the breadboard setup.
DSC00496.jpg (381.66 KiB) Viewed 834 times
DSC00497.jpg
Wires soldered to the in side of the strip.
DSC00497.jpg (326.9 KiB) Viewed 834 times
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Re: LPD8806 chips getting hot enough to burn skin

by adafruit_support_rick on Mon Nov 12, 2012 8:51 pm

Not sure what could be causing the heat, but the other symptoms sound like the 5V is sagging.

How long is the strip? Any idea how much current the PS will provide? The strip wants about 2A per meter.

What's at the other end of the strip? Is it just open?
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Re: LPD8806 chips getting hot enough to burn skin

by slurry bowl on Mon Nov 12, 2012 11:26 pm

Nakedhoof did you get your problem resolved ? seems your panties were in a bunch
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