GE Profile wall oven Model JPT20BF

Hope this isn't too wordy. New at the forum thing...

Scenario: Someone gave me a nice working GE Profile wall oven model JTP20

Existing Magic Chef (worked just fine) oven is hardwired along with the electric range top to (two) hots (10ga I believe) and one 10ga stranded aluminum as ground in a 100amp SUB Panel. The 400amp main panel is on the other side of the house. The sub panel is in the garage.

Problem:
1. I removed the magic chef oven to replace it with the GE Profile. I wired the ground to the ground from the feed and ignored the white neutral.

2. Before pushing it into the cabinet space I tested everything and it all worked fine. I shut off the breaker, pushed it into the wall, turned on the breaker and nothing. No lights, no clock. the range top works but absolutely no lights on the oven. No way to reset the oven (according to manual) because there are no lights.

3. Shut off the breaker for 10 minutes and tried again. Nothing. range works fine (both wired together in gang box).

4. I pulled the oven figuring I had a loose connection. All good. tested both leads are hot.

5. Tested power from the romex at the junction box and going into the oven's interior connection. There's 240 power all the way through. 120 on each leg to ground.

6. Gave up and re-installed the old magic chef oven. Turned on the breaker and now THAT oven doesn't work either!!! No lights! Nothing. The range top still works fine.

7. I find it hard to believe I burnt both controller boards but I've done worse in my life.

Last effort: I have a 240 outlet in the garage on a separate circuit. I bought a 50A plug to match, attached it to the GE profile and plugged it in. Nothing. Haven't tried the magic chef yet. Should I try connecting the white neutral to the feed ground instead of the ground?

Humbled and hoping someone can help.