System-board switches, jumpers, and buttons

The following illustration shows the location of the switches, jumpers, and buttons on the server.

Important

• Before you change any switch settings or move any jumpers, turn off the server; then, disconnect all power cords and external cables. Review the information in Safety, Installation guidelines, Handling static-sensitive devices, and Turning off the server.
• Any system-board switch or jumper block that is not shown in the illustrations in this document are reserved.
• If there is a clear protective sticker on the top of the switch blocks, you must remove and discard it to access the switches.

Figure 1. System-board switches, jumpers, and buttons

The following table describes the jumpers on the system board.

Table 1. System board jumpers

Jumper number	Jumper name	Jumper setting
J11	Clear CMOS jumper	Pins 1 and 2: Normal (default). Pins 2 and 3: Clears the real-time clock (RTC) registry.
J13	UEFI boot backup jumper	Pins 1 and 2: Normal (default). Loads the primary server firmware ROM page. Pins 2 and 3: Loads the secondary (backup) server firmware ROM page.
Note If no jumper is present, the server responds as if the pins are set to the default. Changing the position of the UEFI boot backup jumper (J13) from pins 1 and 2 to pins 2 and 3 before the server is turned on alters which flash ROM page is loaded. Do not change the jumper pin position after the server is turned on. This can cause an unpredictable problem.

The following table describes the functions of the SW3 switch block on the system board.

Table 2. System board SW3 switch block definition

Switch number	Default position	Description
1	Off	Reserved.
2	Off	Power-on password override. Changing the position of this switch bypasses the power-on password check the next time the server is turned on and starts the Setup Utility so that you can change or delete the power-on password. You do not have to move the switch back to the default position after the power-on password in overridden. Changing the position of this switch does not affect the administrator password check if an administrator password is set. See the user security section in Setup Utility menu choices for additional information about passwords.
3	Off	Reserved
4	Off	Reserved

The following table describes the functions of the SW11 switch block on the system board.

Table 3. System board SW11 switch block definition

Switch number	Default position	Description
1	Off	Indicates a physical presence to the system TPM
2	Off	Reserved

The following table describes the functions of the button on the system board.

Table 4. Button on the server

Button name	Function
Force NMI button	This button is on the rear of the server. Press this button to force a nonmaskable interrupt to the microprocessor. You might have to use a pen or the end of a straightened paper clip to press the button. You can also use it to force a blue-screen memory dump (use this button only when you are directed to do so by Lenovo Support).