Fail of the Week: WS2811 Pixel Failure on FLED


This Fail of the Week project comes from one of Hackaday’s own. [Ben] took on the FLED data visualization project as a way to make the SupplyFrame decor a lot more fun. He had quite a bit of help soldering the 96 WS2811 pixels into their custom made 6’x4′ enclosure and the results are really awesome. In addition to showing server load and playing games, FLED has become something of a job interview. Sit the prospective employee down at a terminal and give them an hour to code the most interesting visualization they are capable of.

But two weeks ago [Ben] staggered into the office and found the display was dead. Did he try turning it off and back on again? Yes, but to no avail. The power supply wasn’t the issue and there was no option but to pull the display off the wall and crack it open for a look at all those pixels. Since every one of them had 4 solder joints on either side he figured the problem was with a broken connection. But not so. He resorted to a binary search for the offending pixel by  cutting the strand in half, and testing each portion. He tracked it down to the pixel whose underside was blackened as you can see above.

[Ben] thinks one of the capacitors inside the sealed enclosure blew, but isn’t certain. Feel free to tell us what you think failed in this component. But the thing we’d really like to know is if there is a more clever way to sniff out the offensive pixel without cutting the connections? Four hours on the floor with this thing (and no knee-pads) and [Ben] has sworn off sourcing pixels from random Chinese suppliers. He might go with pre-assembled strings next time. We chuckle; this is the high-tech equivalent of trying to get old strands of Christmas lights to work.

If you haven’t seen FLED in action, check it out after the break. It amazing how LED intensity and quality diffuser material can make a perfect grid of LEDs seem to dance in waves and color curves.

[Read more...]