When I try to boot my computer I get nothing

[helpdesk98]

I have a Windows 7 computer

power supply 700w

AMD 7870 graphics card

16 gigs of ram

4 core processor amd

My computer randomly crashed after a game I play Planet side 2 crashed,. When the game crashed I just figured it was just the reoccuring server issue they've been trying to fix that week. I then went on to facebook then my computer just bit the dust. Everything turned off instantly after that only the tower turns on I can tell by the lights.

I tested my monitor on a laptop and that worked fine, and all my other devices (mouse, keyboard, wifi flash card) work just fine too on the laptop but once plugged into my desktops tower, will cease working. I've reset the cmos, even took out my new graphics card (mentioned above) and still nothoing displays or works other than the tower. Thanks for anyhelp. Sorry if this is posted in the wrong section.