I am glad I could help you find the problem.
Now you have to decide if you want to change the control board or fix the solder joint. If you have and know how to use a solder gun you can repair this board and save money. However if the solder joint is bunt so bad that it has damaged the surrounding circuits you will have to replace the board. Also if you do not know how to properly fix this it will not last long.
Clean the joint as well as you can, and then place the board on a flat surface. Get your gun good and hot then heat the joint that is to be repaired. When everything is nice and hot touch the end of the soldering iron briefly with the solder. The solder should run down onto the joint and make a pretty joint.
Replace the board if
1. If you are uncomfortable doing this repair.
2. If the joint is burnt too badly.
3. If repairing the joint doesnt correct the problem.
4. If the joint you repair ever fails again.
5. Once the repair is done check and make sure that the oven will cycle. If it continues to heat (gets too hot) the relay on the board is bad so replace the board.
I believe that sometimes when these boards are manufactured a solder joint may not get enough solder or something to that nature.
A lot of techs will recommend replacing the board no matter what. I dont necessarily disagree (it is not bad advice) but I have been successful doing this type of repair many times.
I hope this helps!