Sun Microsystems Ultra 1 Creator Series Service Manual page 48

2. Verify the keyboard LEDs light to confirm the system is in the POST mode and
the keyboard Caps Lock key LED flashes on and off to indicate the system has
enabled the POST.
3. If a failure occurs during POST, a keyboard key LED other than the Caps Lock
key LED may light, indicating a failed system component.
See Section 3.9 "System and Keyboard LEDs" on page 3-12.
4. If the Caps Lock key LED fails to flash after the Stop and D keys are pressed,
POST has failed.
See Section 3.9 "System and Keyboard LEDs" on page 3-12.
Note – The most probable cause of this type of failure is the system board.
However, optional system components could also cause POST to fail.
5. Before replacing the system board, remove any optional components such as SBus
cards and memory, and repeat the POST.
Note – Non-optional components such as: two DSIMMs in slots U601 and U701; the
system board; the power supply; and the keyboard must be installed for POST to
execute properly. Removing the optional system components and retesting the
system isolates the possibility that those components are the cause of the failure.
6. To receive additional POST failure information, establish a tip connection.
See Section 3.2.1 "Setting Up a Tip Connection" on page 3-2.
3-14 Ultra 1 Creator Series Service Manual • August 1996