I was at a friend’s house last night. She had bought two used electronic 1000 watt ballasts off ebay months ago. The first one immediately tried to catch on fire when plugged in. The second one seemed ok. Now, a few months later, I just noticed that it has melted one side of the plug and the timer it was plugged into. I had seen old magnetic ballasts do this, but never an electronic one.
Obviously that ballast is not getting used again, but what exactly is happening to make ballasts melt plugs like that?