Like the title says, I've got an old single priced DN 501E on site that's giving me hell. I've swapped 3 cooling decks with each one lasting about a week. I thought I was just having bad luck and grabbing bad decks or something, but on the last one I pulled it from a working machine and it did the same thing to it. I tested the outlet and am getting a firm 120 from there. So, where do I look next. Power supply? What else is there on these old machines that could be burning up the decks like this so quick?