Not positive what caused the converter to die, but it has had a rough life. It spent most of its life plugged in 24/7/365 and did that until I bought the unit in 2011. Again it stays plugged in with me all summer. I took it up for a week of archery hunting last year and we ended up with MICE everywhere. I ended up removing 11 of the little monsters before the week was out. It kind of looked like maybe a mouse had peed on the circuit board but I never could figure out how it would have gotten into the box as that thing is sealed up pretty tight. Don't know for sure.