After waking up this morning and walking over to my (custom built) computer to wake it up (I always leave my computer on), I noticed my computer was going extremely slow. It took a minute to wake up and show the login screen and then after logging in (I could type at normal speed with characters being entered in on the screen at the same time I type them though) it took another minute to show the desktop. When it got to the desktop, there wasn't any mouse. I tried hitting control+shift+escape to get to the Windows process manager but that wouldn't come up. It was almost like my computer was frozen. I then attempt to hit the restart button on my case, nothing happens. I held down my power button on the case for 15 seconds, nothing happens. I switched off the power feeling like no other options left and kept it powerless for several seconds, and now it won't turn back on at all.
I'm thinking it might be the motherboard that has gone? Any ideas on what it could be or how to test it?
(As a side note, I am not sure if it matters, but I just put a new GTX770 in it this week too)