Key pad will not work on my oven except for the convection roast button

you can recalibrate it yes.

https://forum.appliancepartspros.com/posts/t191937-thermador-oven-temperature-thermostat

It's on page 32 of the manual for Thermador's built in convection ovens.
1. turn off the oven
2.touch and hold the start pad and then touch the bake pad
3. 0 (zero) appears in the temp digits. release all pads
4. touch bake and 0 changes in increments. max adjustment is 35 degrees F.
5. to complete change touch start for lower oven on double ovens do this: touch the roast pad instead of the bake pad continue with steps 3-5.

Please always include full 'make model (what it is)' in all questions.

Depending on your model, you may find replacement membrane switches for your touchpad here, (even if they are no-longer-available from the OEM):


Introducing the Ledgestone Technologies Touchpad

ensure that your convection fan is turning
a hum on this model usualy means that the convection motor can seize up a bit
sometimes all you need to do is redjust the fan blade

The good sign is that the motor works fine as do heaters. If the operator interface acknowledges feature selection by beeping or what have you, we can safely say the problem lies with the control board or relay.

With all that you said, I would suspect an open or faulty element. It is pretty much the most obvious solution.

If you have any electronically ability and you are going to open the oven, use an ohm or resistance meter, check the amount of ohms and use the upper element as a reference for the correct reading.
The element will either read open or good. You can use a light tester also and if the light lights between the two connectors of the elements, then it is ok and look elsewhere.

E

I would suggest that you check the oven element, it sounds as though it is faulty to me.

Did you try going to the GE website? If not, try it:

http://www.geappliances.com/

When you pull up the website, you can click on the blue down arrow located in the box at the top of the web page, next to the work SEARCH and click on "USE & CARE MANUALS. Put your model number into the next box to the right and hit GO.

If you are having trouble after entering what you believe is the proper model/serial number, you can look at the FAQ (frequently asked questions) section to determine whether you have actually entered the proper number.

I am by no means an expert, but I believe the only thing differenty in a convection oven vs a regular oven is that there is a fan to conduct the heat quicker and more evenly. It has to do with heat tranfer rate. I can't imagine why aluminum foil would cause any problem.

Check for a bad fan motor or a jammed blade.