I bought a new motherboard and 550 psu yesterday. Got home plugged everything in - LCD on front of tower says no power. The psu fan doesn't spin, the cpu fan is dead - no activity at all. It just sits there like a massive doorstop. I've tried clear CMOS I've checked all my leads and connectors. Can anyone help me figure out weather this is a m/b problem or a psu problem? It's a gigabyte GA-7N400 Pro 2 motherboard with 1gb DDR400 memory. My processor is a AMD Athlon XP 3200.