The controls light so I know it's getting power, but that's it! I had not used it for about three months. Last time I used it it was fine. Any idea what might be going on? How to fix it?
I guess it is worth asking if you are testing it with a suitably inductive pan.
If so, there are two paths to a solution. (a) Buy a new, preferably better unit. (b) Become an electrical engineer or electronics technician and go through the guts determining what failed and what replacement part you can use in place of the failed part.
Path (b) is more expensive than buying a quality unit from CookTek. CookTek is a US company that likely will be around for a while to support their products. I have their 3500W wok unit.