Start with a piece of cardboard or the motherboard box to make it outside the case with as few parts as possible. That must work first then into the case being sure there are no extra mounting posts.
So about 2 weeks ago i came home and started my computer, it started up and then shut down. I tried starting it again but it didn't work. It was dead. I have bought a new power supply, motherboard and ram. Nothing worked. After i replased the motherboard the pc started again, but now it boots up then shut down over and over again. You can hear a tik sound from the SSHD right before it shuts down. SOMEONE PLEAS HELP =(