A few things you can try:
- Check and double check all of your connections.
- Perform a BIOS reset (check the motherboard documentation on how to do this).
- If you have on-board graphics, try booting with that and not the discrete GPU.
Well i have just spent the last few hours trying to fix this. I have taken out my motherboard multiple times and plugged in all the cables again. I have also tried reseting the BIOS but nothing would happen and I have also tried using onboard graphics but still no luck. Same thing keeps happening, starts up after being left a couple minutes then turns off almost instantely.