Check the back of the power supply. If it has a light on it, does it light up when you have the switch in the on position (the switch on the psu)? If not, it could be the power supply. But assuming a surge hit it, and took out the power supply, I would suspect the motherboard got hit as well.
So, if it does have a light, but refuses to light up, or doesn't have a light at all, I would suggest you start by trying to get another power supply and seeing if it works (maybe borrow one out of another computer, or from a friend, for testing purposes, or you could always buy one, test it, and return it if it didn't solve anything). Assuming the power supply isn't the issue, I would say the motherboard is fried (usually is if no lights or fans come on or even blink).
Here's a list of suggestions to try:
1: Plug it into another power source, another wall socket in some other room. If it was plugged into a power rail (thing you plug in that gives you more sockets to plug into), try using the wall socket. The power rail could have faulted and broken.
2: check all the connections in the computer, make sure the power cables didn't come loose. Make sure the power cable is snugly in the power supply itself.
3: Test with a different power supply. (optional) buy a power supply tester, and test the power supply. You don't want to test the power supply on another computer, because if it's broken enough, it may very well fry the motherboard when you turn it on.
4: Still no luck? You probably need to replace your motherboard.