My computer will not turn on.

I have an HP Pavilion. The computer was working perfectly fine up until a few hours ago. The power went out on my street. The first time it went out it only went out for a brief moment before it turned back on again. The printer started going and the monitor clicked on like it usually does when my computer restarts. I thought about turning the computer itself on my I decided against it because I had no need to go back on at that moment. Good thing because a few seconds later the power went out again. I don't even think the power was out for more then a half hour. About an hour later I wanted to use the computer again. I went to turn on the computer but it wouldn't go on. I turned off the computer and then I turned it out again. The printer turned on and the monitor (screen) was on but the computer tower would not turn on. I haven't a clue what is wrong with it. Nothing like this has ever happened before. If someone could help me out or give me a few suggestions that would be great! Thank you =)