Re: Bad LEDs?
Well, as Alice would say, "curiouser and curiouser".
I took the board that has the most "bad" leds on it. Six, two on one side and four on the other.
I took a known good blue led from the baggie of leftovers, tested with a laboratory power supply.
I tacked it on to each bad led in turn. Four of six times not only did the tacked on led light, but the suspect one lit too! :shock:
Just to keep things more interesting, two out of the six bad leds did not light, but the tacked one did. :?
What the heck am I looking at here? Flakey solder joints that fix when I tack on a led and then fail again when I take it off? I tried reheating and adding a little more solder. Fail. Flakey outputs on the shift register chips or insufficient output loading? :?:
Thanks for any and all suggestions.