US Patent 7774633 Controlled power cycling in computing devices

Cycling power in a computer to clear hang-up conditions may include disabling low voltage DC signals between an output of a standby DC power supply and standby-powered circuits in response to a power cycle request. In response to a disable signal, a power cycle module (PCM) may disable standby power being supplied to standby circuits in a computer, server, or router, for example. In addition, the PCM may disable power to main circuits by, for example, generating logic-level control signals to the power supply, or by opening a series-connected switch through which main current flows. In response to a re-enable signal, the PCM may re-enable the supply of standby and/or main power to a computer.