Well, we knew from the set of LEDs that were apparently connected that there was a partial short between LED1 and LED2, or a defect at D21 or D12, the two LEDs between those lines. When we received it, I checked those two LEDs. D21 worked fine, but D12 did not, so I clipped one of its leads to see if that LED was the issue, or if it was external. Turned out that even isolated, D12 would not light up, so it was apparently the culprit.
I’m not sure what went wrong with it; it could have been stressed during lead-bending or soldering. But, I’m glad that it’s working now. :)
