the pc ballast is internal in the coralife lights. some have 1 ballast for each bulb some have 1 ballast for 2 bulbs

Thanks. I'll take it apart tomorrow and see if I can get new ballasts.

Don't be surprised if all you find inside the light housing is a couple of transformers and other small components wrapped in heat shrink. I could be wrong though and there may be a generic flourescent ballast (or two) in there. Have you tried new bulbs yet?