Too many nuances on this one to have a pat answer as to what a judge or magistrate would do. The issuing officer must be present. Ya can't cross examine a piece of paper. These "trials" in metro courts in the US, last seconds. Best defense IMO in this one particular scenario (an inoperable signal) would be documentation from traffic engineering. Some major difference in subpoenas in US Fed and "muni" courts. All pretty much fact excepting New Jersey I gather, where the spirit of Judge Roy Bean lives on and Tony Soprano makes up the rules.
I just find the sensor kerf in the asphalt and lower the sidestand down onto it, seems to work for me.............
Nothing I've tried works, not even the bogus trip sensor I mounted under my bike. I just run the light. I am going to try Bear's suggestion, though. It better work!