Lenovo 3797 manual Power-supply LEDs, Server power features, Turning on the server

Power-supply LEDs

The following illustration shows the power-supply LEDs on the rear of the server. For more information about solving power-supply problems, see the Hardware Maintenance Manual.

1 AC power LED (green)
2 DC power LED (green)

3 Power-supply error LED (amber)

Server power features

When the server is connected to a power source but is not turned on, the operating system does not run, and all core logic except for the Integrated Management Module (IMM) is shut down; however, the server can respond to requests from the IMM, such as a remote request to turn on the server. The power-on LED flashes to indicate that the server is connected to power but is not turned on.

Turning on the server

Approximately 3 minutes after the server is connected to power, the power-control button becomes active, and one or more fans might start running to provide cooling while the server is connected to power. You can turn on the server and start the operating system by pressing the power-control button. If a power failure occurs while the server is turned on, the server will restart automatically when power is restored.

For 32-bit operating systems only: Some memory is reserved for various system resources and is unavailable to the operating system. The amount of memory that is reserved for system resources depends on the operating system, the configuration of the server, and the configured PCI options.

Turning off the server

When you turn off the server and leave it connected to power, the server can respond to requests from the IMM, such as a remote request to turn on the server. While the server remains connected to power, one or more fans might continue to run. To remove all power from the server, you must disconnect it from the power source.

Important: To view the error LEDs on the system board, leave the server connected to a power source.

Chapter 4. Server controls, LEDs, and power 31