I just ran across that yesterday. The lightbulb thing. I think it was a Watermaster timer with the switches that slide up and down for the zone run times. It might be the transformer. Touch it and see if it's cold.
You might have a bad solenoid on one of the valves that shorted out the timer. I don't recall if there's a fuse on it or not. I fixed it before getting that far. Look for a reset button or a fuse. If it's a solenoid it will probably blow the fuse again. Just watch and see what station number it is and go from there.
Good luck!
If I can't fix it, it's broken!
