System-board switches, jumpers, and buttons

Use this information to locate the switches, jumpers, and buttons on the server.

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

Note

If there is a clear protective sticker on the top of the switch block, you must remove and discard it to access the switch.

system board jumpers and switches

The following table describes the jumpers on the system board.

Table 1. System-board jumpers.
Three column table with headers documenting the number, name, and setting for applicable jumpers.
Jumper number	Jumper name	Jumper setting
J71	UEFI boot recovery jumper	Pins 1 and 2: (default) Loads the primary UEFI firmware ROM page. Pins 2 and 3: Loads the secondary (backup) UEFI firmware ROM page.
J86	IMM low security jumper	Pins 1 and 2: Removes the security check, allowing unsigned IMM2 firmware. Pins 2 and 3: (default) Allows only signed IMM2 firmware to be flashed.
J115	IMM recovery jumper	Pins 1 and 2: (default) Loads the primary IMM firmware ROM page. Pins 2 and 3: Loads the secondary (backup) IMM 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 recovery jumper 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 SW7 switch block on the system board.

Table 2. System-board SW7 switch block descriptions
Switch number	Default position	Description
1	Off	Reserved
2	Off	Clear CMOS memory. When this switch is toggled to On, it clears the data in CMOS memory, which clears the power-on password.
3	Off	Reserved
4	Off	Reserved
5	Off	Reserved
6	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. Note 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 Passwords for additional information about passwords.
7	Off	Reserved
8	Off	Reserved

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 blocks that are not shown in the illustrations in this document are reserved.

The following table describes the functions of the buttons on the system board:

Table 3. Buttons on the server
Button name	Function
Light path button	Press this button to light the LEDs on the system board when the power source has been removed from the server.
Force NMI button	This button is on the rear of the server. Press this button to force a nonmaskable interrupt to the microprocessor. You can also use this button to force a blue-screen memory dump (use this button only when you are directed to do so by Lenovo Support). Note You might have to use a pen or the end of a straightened paper clip to press the button.

Give documentation feedback