thermador SC301 does not bake

Hi everyone! I have a 8 year old Thermador SC301 Wall Oven that suddenly stops baking.

When set to bake and given any temperature target, bottom and top heating element does not come on. No fan comes on.

Broiling still works. Can feel heat from top heating element when set to broil, cooling motor comes on.

When set to convection bake, convection fan comes on, but no heat from bottom heating element.

When set to convection roast, convection fan does not come on, no heat from bottom or back heating element.

I already tested bottom heating element. It is not broken per continuity test.

I have tried resetting High Temperature Cutoff. It didn’t do anything different. If the oven broils, I can rule out HTC as the problem, right?

What do you guys think is causing the problem?

Could it be the cooling fan? The cooling fan comes on when I set it to broil. It’s supposed to come on when set to bake, right? Why doesn’t it come on? How do
test to figure out what’s wrong with it?

Could it be the air switch? Pardon my ignorance, but why is air switch needed and how does it work? If I have to replace or test it, how to access it?

Thanks in advance!

I was going to do some testing on the board to see why cooling fan doesn’t come on when I set it to bake, but comes on when I set it to broil. Any advice where I should start?

Also, how can I pull out the top plenum so I can access the relay board?

http://www.appliancepartspros.com/partsearch/model.aspx?model_id=232432&diagram_id=194156#d194156

my unit SC301ZP does same. Technician installed new board and now unit will not even light up/ I need a wiring diagram.

Hi.

Find below the attached manual.

Thank you.

Simon.

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