The Secure position (
The Secure position prevents the system from doing an IPL. If the operating system is
already loaded, this position does not lock the system console or block system network
When loading the operating system with the Key Mode Switch in the Secure Position a
200 is displayed. If the Reset/Scroll button is pressed at this point the system resets and
goes through another boot process until a 200 is displayed again.
When the operating system is running, turning the key to the Secure position disables the
Reset/Scroll button. With the key mode switch in this position, a passerby cannot
accidentally press the Reset/Scroll button and cause a loss of data.
The Secure position prevents an autoboot in case of a system crash or checkstop
The Service position (
Attention: The Reset/Scroll button is active when the key mode switch is in the Service
position. Pressing the Reset button can cause data to be damaged or lost if the operating
system is running.
The Service position is used for attended operation when hardware or software service is
performed. The Service position activates operating system console sequences that
support error determination (debug) and storage printout (dump). In the Service position,
the system unit attempts to IPL from the media drive. The IPL proceeds according to the
Service Mode Bootlist.
The key mode switch is also used for the following:
To indicate to the diagnostic programs that there is no console available. This is done by
changing the key from Service to Normal and then back to Service when a c31 is
displayed on the operator panel display.
To start a dump: If the system is running in Normal mode, a manual dump is started with
the key set to Service and pressing the Reset/Scroll button. If the system is running with
the key set to the Service mode, a dump is started by setting the key to Normal and
pressing the Reset/Scroll button.
If there is a problem with the system unit, refer to the AIX Version 4 Problem Solving Guide
and Reference before setting the key mode switch to the Service position or before pressing
the Reset/Scroll button.
Attention: Do not set the key mode switch from Normal (OK) to Service while the system is
booting. Instead, wait until the boot is completed and then change the mode switch setting.
Using the CPU Enclosure