Computer crashes, lights and fans still function. Requires power cycling.

[Lungjaw]

I built this computer just a little over a year ago, and this problem has been occurring for the last few months.
It's been really difficult for me to pinpoint the origin of this problem because it seems to happen at arbitrary times. Sometimes during gaming, sometimes during browsing the web, working, or when doing nothing at all.
My computer will freeze but every component's LEDs in the case will remain on and the fans will still be spinning. Anything in the USB ports will lose power usually, however. My monitor continues to display.
I've had to cycle the power whenever this happens and the computer will turn on, then off, then on again 3-4 times before turning on properly. This tends to happen when I wake it from sleep mode as well.

This issue happens, at most, once or twice a day.

Specs:
Windows 8.1 32Gigs of RAM
Motherboard: Asus Z97 Deluxe
CPU: Intel Core i7-4790K "Devil's Canyon"
GPU: Nvidia GeForce GTX Titan Black
PSU: Seasonic Platinum 1000 Watt
Case: Antec Twelve Hundred V3 Black Steel ATX

Thank you.

 

[Lungjaw]

It's happening more often than ever today. I've tried all sorts of maintenance. Re-applied thermal paste to my CPU. I blasted every fan with compressed air. I reset my CMOS. took my RAM out and put it back in. I don't think my power supply could be insufficient. Maybe defective? I'd like to know for sure before buying anything new. Does anyone have any insight on this? I do a lot of 3D modeling on this computer and my productivity is plummeting.