I have an older Ice Cap 660 ballast running four T-5 bulbs. The setup has been working for a good 8 months or so with no issues. Now, it is not working. If I unplug the ballast and then plug it back in, it all lights up but quickly shuts off. I'm guessing some type of short, but I'm not sure how to figure it out.

The ballast is a good 10 years old. The lights are 8-10 inches off the water surface. The wiring harness is also 10 years old and was used before to run two VHO actinics when I used to have halides. The T-5's are the only lights on this tank.

Any ideas?