Given the lights were still on after, that makes me wonder if you shorted a gi to something, thus grounding the coils, and displaying the residual voltage as the solenoid circuit drains after turning off which you saw in the string of LEDs being on for a while after. Examine all sockets for this string of gi.
Also for ribbon cables, sometimes people flip both ends so that pin on the board is not with the red stripe, but both ends are like this. This sometimes get you by a faulty ribbon issue, I have done this at least once. I always check both ends now whenever I disconnect them.
La Porte, TX
