Well explained, thanks for the video. One question. As you stated, you did that in a safe way without endangering your lights so there really was no risk to implementing this same testing strategy with all the pixels at once, so why bother? Unless biasing these backwards would blow them given the voltages used. Is there an advantage to using 2, rather than just 1? Having 2 allows you to observe the data being passed along, but assuming you are feeding the data in the correct side, it should light a single one also. Regardless, the pixels can be salvaged for spares/replacement down the road, so it's no loss either way.