Bad Power supply #1, bad mobo #2 bad ram #3, bad vid card #4, start pulling components one at a time until you can get into bios, if your down to mobo/psu/vid and the same thing time buy a new psu and mobo (check the return policy make sure it's 30 days for any reason), try the new psu on the old mobo, if that fixes it return the mobo, if not it's time to either install the new mobo or time to start from scratch depending on your current gear..