I'm installing a new motherboard and processor - ASUS A7V8X-X with AMP 2500 XP. I've inserted the motherboard, connected the processor/heatsink/fan, conncted drives and PCI boards. Last I connected all of the power cables and pin connectors. When I try to start the machine everything lights up but the CPU fan doesn't start, so I switched it off immediately. Any idea why the fan wouldn't work? I tested the fan in a different machine and it works fine. I also tried a good fan in the macjine but it didn't work.