atwood 7920 hydro flame furnace

I've got a 2007 keystone hobbi 265 that's new to me. I've owned it about a month or so. Heater worked when I picked it up. Used it at home for a week or so as we loaded up and played with our new toy. Hauled it out for our first weekend and no heat. It did nothing, no blower or anything. single blinking light. Got home and started checking things out. sail switch, limit switch ignitor all good. So I replaced the control board with a Fenwal board #35-535811-113. All good, again used it at home , took it out for the weekend worked great. Got home and no heat again. Exact same issues.
My question is , is there something else causing the board to go bad or is it just my dumb luck to get a bad board. Your help is greatly appreciated, as its getting COLD in Michigan.