Was wondering if anyone could give me a few ideas on where to look to fix this issue.

We were using the microwave as a timer, and we think we turned it on without anything in it for about 20 minutes or so.

It won't power up now. I've checked the fuse and it appears that it is working, used my multi-meter to test the voltage in a few areas and it appears to be getting the correct voltage however the display is still blank.

Looking at the data sheet, and the flow chart it says to check the power supply, flame sensor, or the control xfmr volts are ok? What's the best way to check the flame sensor, and what exactly is the xfmr?

Thanks for any tips.
Dd.