Lenovo Flex System x440 Compute Node Installation And Service Manual page 32

The following table describes the functions of the switches on switch block SW3.
Description
Switch number
U52-1 Password override
U52-2 Trusted Platform Module
(TPM) physical presence
U52-3 Real time clock (RTC) reset
Lenovo Flex System x440 Compute NodeInstallation and Service Guide
22
U52 and U9020
switch block
Switch setting
The default position Open.
The default position is Open.
The default position is Open.
Definition
Changing this switch to the
Closed position overrides the
power-on password.
Changing this switch to the
Closed position indicates a
physical presence to the
TPM.
Changing this switch to the
Closed position resets the
RTC. A momentary toggle is
all that is required. To avoid
excessive CMOS battery
drain, do not leave this switch
in the Closed position.