I have a customer with a portable flashing arrow sign that is permanetly mounted. The fluorescent bulbs were not working. I found a wire shorted on the frame. Repaired it and replaced the ballast (T12HO). It was working fine when I left. A few days later they called and now the fluorescent lamps will light for 1 second when the sign is turned on and then go out. I can turn it off and back on and it lights 1 second and then goes out again. Ballast?? I just put a new ballast in it.
