GE repair came to house - they said it was a TC and put it on order. Part is NOT available. Most likely cause was board, TC was cheaper (theoretically) - so I bought the board and seems to have fixed the problem. A lot cheaper than having them repair it. And though the job was very easy seeing the online video made me feel more comfortable doing the job myself
the toughest part of the job was finding the star-shaped head to take part of the oven apart to replace the part! it looked like an allen key head in poor light