Thermador wall oven control

I recently used a repair service recommended by Thermador. He is not responsive. He told me I would need to replace the touch panel. He searched for parts and said he could not find the necessary parts through Thermador or Bosch. I found the part at AppliancePartsPro but it did not resolve the problem. I now have a $300.00 part but the oven control still does not work. I now suspect it is the display board but I am not sure. I have not been able to get the repairman to return my calls so I guess I am stuck. Can you help me troubleshoot my problem. I know I am getting power to the display but none of the touch screen points seem to work other than a steady beeping sound. By the way I think my repairman may have damaged the original touch panel when he pulled the 4 pin plug. There was a disconnect attachment that he did not notice. How do I proceed. I would hire a repairman but no one will work on Thermador.