I just purchased a couple of strands of the "20mm Clear Digital RGB LED Pixels" (20 pixels per strand, with LPD6803 drivers), and there appear to be a some dud pixels in each strand.
On the first strand, one LED has the green permanently on, and another has a dimmer red than the others. Also the "output" side of the strand is missing the power and data connections, and cannot therefore be chained to another strand. On the second strand, one of the LEDs flickers brightly, and another has no red (pictures below).
I'm using an Arduino to supply the control signals (running various test sketches based on the code at https://github.com/adafruit/LPD6803-RGB-Pixels
). The LED power is coming from a separate 5V regulated supply (commoned to the Arduino ground).
Any help welcome. Thanks,
Here's a movie of the second strand, programmed to a uniform mid-brightness white: http://timgiles.free.fr/forumpics/led-string.mov
And a couple of still views of the end of the same strand. The 4th LED in the picture is flickering brightly, and the 5th has no red.