No GPU output after computer restart

[Guest]

My rig;
i7 3770k
Geforce GTX 670
AsRock Z77 Extreme 4
16GB 1600mhz ram

Problem:
I was browing 4chan as you do and I saw a few corrupt images, I thought I might had needed to restart my PC as it had been on for 18 hours, gaming and so forth.
I click the restart button and I get no display, I know my computer has actually started due to the distinctive Windows 7 start up noise, I could also type my password in and hear the log-in noise.

I am currently plugged into my motherboard's on-board graphics. (Intel HD 4000)

Things I've tried:
I have already cleared my CMOS
Pulled my power plug for a few minutes
Going into msconfig and selecting the 'base video' checked option

What should I do?

 

[Guest]

I decided to pull the upper power cord from my GPU, I did so while the PC was running, I then plugged it back in and restarted it.
Doing so seemed to fix it for me.

And for some reason, after I unplugged the upper cord, the fan literally spun the fastest it should ever spin. It was going so fast I was a little worried so I went to stop it with my finger by slowly putting more pressure on the middle of the fan, and I felt burning on my finger. -- just something random

 

[truegenius]

its normal for a gpu fan to go 100% whenever it detect no 6 pin power cable ( if it have 6 or 8 pin connector )
it could be smps problem, loose connector, overheating
which smps you are using ?
and check you cpu/gpu temperature while idle and while 100% use