I have a Z87 Classified that decided it no longer wants to power on. It was sitting for a week or so without use, then I pulled the graphics cards to take photos of them, replaced them, and it will no longer power on. The power is getting to the board, as the power button is lit up green as well as the white led next to the BIOS selector switch when the power supply is switched on. When pressing the power button, nothing happens.
 
I have isolated it to the motherboard, removing it from the case, removing all cards, down to 1 stick of memory and trying again, with no success. Trying the reset CMOS button does nothing. Removing the battery does nothing.
 
I have tried 3 power supplies (Antec HCP 1200, Antec HCG 750, Corsair TX650) all with no success.
 
I swapped out the CPU with another CPU, also with no success.
 
Before RMA'ing it (if I even can) is there anything else to try? It was working fine before that week of resting. I have seen similar problems from other posts, but it always seemed to get fixed by a different PSU, which is not the case here.

Sounds like you've done all the relevant testing for the issue you're having.  There's nothing left you can do short of doing things that would void your warranty.  
 
Time to contact EVGA's Support:  http://www.evga.com/about/contactus/
 
 

I'm having a similar problem with my Z87 Classified.  If Windows crashes to the point that CTRL-ALT-DEL doesn't work, when I manually power down the computer, the power button doesn't work to restart it.  I've noticed that instead of the usual red and white lights on the motherboard, only the white LED is lit.  I have to unplug the power from the back of the case several times and after 3 to 5 minutes the power button will again work.  I got this motherboard in June 2014 and this problem first appeared about 4 months later.  When you shut the computer down normally, no problem, but a hard crash leads to the power button not working just about every time.  Any suggestions would be appreciated and TIA.