Thanks everyone for your help.
The recall box had been checked before looking for your help.
The problem is with the board.
I called Norcold and they refuse to give the electrical diagram ont the board. They want me to ask a dealer, but no dealer has it.
They want to sell a new board.
I brought my defective board to an electronic tech. He found that a small part worth less than a dollar was burned out. It is not he first time that me or my friends have problem with Thetford (Norcold). They, in my opinion, deserve a big ZERO for Customer service. They just want to sell parts. For example, I have replace the rubber Inside the doors. They do not sell the rubber, I have to buy new doors at a cost of +/- 600.$
Could FMCA make representations on our behalf to make these peoples more Customer service oriented. They have a permit to steal from us.