Diagnosis
A power surge during the outage may have tripped the internal safety fuse on the control board. It's a small, one-time fuse that blows to protect the more expensive electronics.
How to Fix It
Unplug the unit. Locate the power cord where it enters the back of the cabinet. There should be a small, rectangular recess with a red or black reset button. Press that button firmly. You might hear a faint click. Now plug the unit back in. This often brings it back to life.
If That Didn't Work
If there's no reset button or pressing it did nothing, the issue is deeper. The next step is to check the main power board fuse, but that requires opening the cabinet (voiding warranty) and using a multimeter to test it. If you're not comfortable with that, it's time for a service call.
Heads Up
For the future, plugging this (and any appliance with a compressor) into a quality surge protector is a cheap insurance policy. The compressor's start-up draw makes it vulnerable to voltage spikes when the power restores.