So I'm trying to build this...
CPU: i5 3350P 3.1ghz
RAM: 1x4gb Crucial Ballistix DDR3
Motherboard: Gigabyte B75M-D3h
GPU: Sapphire HD 7850 2gb
PSU: XFX 550+watt
...and all I'm getting when I boot is 1 long beep and 3 short beeps. The CPU fan spins, the box fan spins, the GPU fan spins for a second and then stops; then the beeps, then the GPU fans start. I thought it was memory at first (I was using memory with incompatible voltage) until I switched out with the above which is 1.5v, with no change. Then I thought it must be a defective motherboard, so I went and exchanged it for a new one, but still no change. I've tried with the onboard graphics, I've tried switching the memory into different slots, and I'm running out of ideas.