Lighting Question

[Mandosh]

I have an IceCap 430 ballast running 110W VHOs. I unplugged the ballast to replace the bulbs and when I plugged it back in the lights wouldn't fire up. Checked the plug and noticed the plastic around one of the prongs was burnt. Plug has been replaced and the fuse in the ballast looks fine but still no light. My question is, am i looking at a wiring issue or did I fry the ballast. Any ideas what could have caused this?