i have similar troubles. when i power on, i get green light on mboard, but when i press power button, fan spins for a split second, then nothing. i still have green light on mboard, all functions cease working after that. reset button, power switch, no hdd light activity, no dvd drive activity. no beeps. has brand new power supply. old e8300 cpu, and old ddr2 ram. checked cmos battery, power good, and jumped bios to 2-3 connector. swapped pcie cards, still frozen system with light on.