Follow up: After I installed the circuit board the part blew out again the next day. The problem was the blower motor. When it fails, it draws too much load and burns the circuit board. Do yourself a favor and replace the blower motor now before you waste the $30 you just spent. You can find it cheapest at
www.rockauto.com and I would recommend getting it with the factory plug-in. I bought the generic version and had to splice the wires together.