Help with old Jenn Air SCE30600W

Hi,
New to the forum and looking for some assistance. Retyping all this after the website says I wasn’t signed in (tho I was). This stove doesn’t want to be fixed…

I have this Jenn Air from buying the house 2 years ago. No manual. No idea how old it is.

In the last day or so, we’ve noticed that things aren’t cooking right. We bought a new oven thermometer and the temp display on the oven reads 400 but the thermometer reads only 275. So am I looking at a new temperature sensor? Is that something I can replace myself? Where’s a good place to buy parts? Or should I just bite the bullet and call the local Jenn Air repair shop?

Any idea how old this range is? The SN is 15031278SK.

Maybe is the parts and service call is $200, the wife is right and we just buy a new range for $500. (Doubt this Jenn Air costs that little, tho).

Thanks!!

David