Need help, don't know what's wrong.

4-pin power lead connected? All the other power cables properly and firmly seated? GPU power connected?

well my professional opinion is that your video card is overheating. lol.

do you have any spare parts to swap in to isolate the problem?

It could be one or several of your hardwares bleepin out at the same time.

I had several hardwares go out like this on my last build after running great for 3 years. It turned out to be a cheap rosewill power supply undervolting.

lol yes i imagine he also had his graphics card plugged in up until it started failing treefrog.

Have you attempted to blow the system out with compressed air? Start there clean out all the fans, reset the cmos and see what it does.

no offense but did you guys read what he wrote? He just built this thing 2-3 months ago tops. Dust buildup is a non issue. plugging in the power cable is not an issue.

watch the next guy ask you to update your drivers without being able to turn your monitor on due to overheated gpu memory. rofling

Ok fine. Well you did say that the fans spin at lower rpm. Have you attempted to reset cmos and also checked the power supply?

and update the drivers ...

Solve the overheating problem. That's a "Duh!".

Then if still broken:
Our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems

I seemed to have fixed the problem for the meantime, but the PC still acts up. Same problems as stated in the original post. Now a couple of the fans won't spin up from time to time, they do light up though.

Unplugging all the fans and lights and starting up the PC solved the problem temporarily. I plugged the fans in 1 by 1 after it booted fine. There's also no beeps or anything, just the noise from fans spinning.

Everything is properly plugged in and seated firmly. I don't have any spare parts on me. Are you guys sure its my GPU and not the PSU?

no, i'm not sure. It sounds likely that it could be the gpu, psu and or the mobo ugg.

I would first try a friends graphics card since nothing is being displayed and over temp protection light is on.

I doubt its your PSU because you have a nice one and its only a few months old.

If your mobo was having an issue finding hardware (memory, vidcard etc) then it would probably be giving you a beepcode before failing to boot.

did you go through the boot fail procedures linked by JSC?