Patent ID: 8209555

Claim:
A computer system, comprising: a first main board and a second main board, generating a first and a second power start signals respectively; a judgment unit, electrically connected with the first and the second main boards to receive the first and the second power start signals so as to output a total power start signal accordingly; a power supply, electrically connected with the judgment unit, the first and the second main boards to output a power reply signal according to the total power start signal; and a first switch and a second switch, receiving the power reply signal and determining whether to output a power good signal according to the first and the second power start signals respectively, wherein when one of the first and the second power start signals is available, the total power start signal and the power reply signal are both available so that the power supply outputs an operating voltage, and when the first and the second power start signals are both unavailable, the total power start signal and the power reply signal are both unavailable so that the power supply stops outputting the operating voltage.