Hard to day. Some systems are set to stay off after a power failure.
Check to seen if there was obvious damage. Smoke, or signs of burning at the wall outlet. Did anybody change the wiring in you office? ( Not a joke. Some places have both 120 and 240 volts outlets in the same room.)
If the power outage did not alter anything, and it is back to normal, recycle your PSU by turning off the switch at the rear and unplug the cord from the wall outlet. It should only take a short time to reset the thing.
Plug it it, ,turn it on and it should work again.
