You are saying that both upper and lower oven bake elements do not work, but both oven broilers work? During preheat, the bake relays will cycle on and off utilizing the broil relays to get up to temperature more quickly. I am looking at your schematic and both ovens utilize one bake relay per oven and one double line break relay for each oven. What is the part number you installed?
I think the part you need is the relay board WITH transformer. That is what is powering your 24 vdc for the relay electromagnets. The part number for that board isNNN-NN-NNNN If you bought and installedNNN-NN-NNNN I think you went for the wrong thing. The transformer/ relay board makes the most sense to me. Also, check all your wiring connectors for any corrosion. If they look ok, go for theNNN-NN-NNNN You're status is showing offline. Since I'm replying to this thread in live chat, I'll change this to Q and A mode. Reply there at your convenience. Thanks my friend. Looking forward to talking with you.
The transformer has multiple outputs. If one of the coils has failed in the transformer winding, that would explain it. Electrically speaking, nothing else makes sense. If the broil does work, that means double line breaks are working and the thermal cut out fuses are intact. So the only other thing in common with both bake relays would be that transformer, L1 and L2. We know L1 and L2 is there because broil works. Here is a link to your schematic.
There is no diagram for the transformer (24 volt circuit) An onboard transformer can power multiple relays. 2, 4, 7, 452 It depends on the windings, and dopes and outputs.