Jenn-Air: Does not heat up on broil or bake

Nursing a Jenn Air along until we get the kitchen remodeled and new appliances. Last night the oven would not heat on bake or broil mode–did not have this problem the day before when we used the oven. Control board seems normal but stays at baseline "100" degree indication. My guess is it’s electrical and not the elements since both suddenly stopped working at the same time. I replaced the bake element several years ago, and since then the control board and temp sensor as well. Checked the voltage going into each of the elements on the back–put one multimeter probe on one of the two prongs and the other probe on the (what I think is) the green grounding wire that screws into the back of the oven and got a reading of 120.

Also, the blower fan doesn’t activate when I turn the switch on–could this be tied to the elements not operating? The broiler fan does come on when broiler is selected, even though the element doesn’t get hot.

If this is a bad relay board, does anyone know where I can get the part #7428P039-60?

Thanks very much.