Originally Posted by
RarestSquirrel
Have you got the right number of pixels set in the config file?
Its just the number on one side of the two strips, not the total of both.
Failing that, and assuming you've got the strips going in the right direction, perhaps desolder and resolder - or desolder then solder just to the strip that's not working to make sure its not dead.
And yes, there should be a 470ohm resistor on the data line and a single 470µF electrolytic capacitor wired to the pos and neg, preferably as close to the start of the strip as possible.