The Sun Fire X4800 server has two power modes, full power mode and standby power mode.
Full power mode is the normal operational mode for the server. When the server enters full power mode, power is supplied to all the server components, the server boots and the operating system (OS) functions. You achieve full power mode by pressing the Power button on the front of the server when the server is in standby power mode. Once the server is operating in full power mode the Power OK LED is on continuously (does not blink).
Standby power is a non-operating mode, in which minimum power is supplied to the components that are required to run the SP. In standby power mode the OS does not boot.
To enter standby power mode, connect the server to an AC supply using the AC power cords, but do not press the front panel Power button. You can also enter standby power mode by powering off the server (from an operational mode) using one of the power off methods.
In standby power mode, the front panel Power LED blinks quickly while the SP is booting, and slowly once the SP has booted. The OK LED on each of the CPU modules (CMODs) blinks while the SP is initializing the CMOD, and remains on when after initialization is finished.