Start by trying to find out what/where the pop was.
There may be some scorching or a weld/arc mark.

I would start by unplugging the unit and checking along the oven elements to see if the ceramic coating on one of them has blown out.
Next remove the back and check the wiring to/from the elements.
Then check inside the control console.

Odds are that the electrical spike that would accompany the pop also blew the control board so you may have a couple parts to replace.