2–2
DECbridge 500/600 Problem Solving
2.2 Normal Power Up
When power is first applied to the bridge, a series of self-test diagnostics, resident on
the AP/AP2 module, is performed. These tests verify the operation of the bridge
hardware before calling the operating system firmware and connecting the bridge to
the network.
When self-test begins, all LED indicators on the bridge I/O panel are momentarily
turned on for a lamp check. During this time a core test is performed to check the core
hardware on the AP/AP2 module (microprocessor, bus, and some of the memory).
Upon successful completion of the core test, the indicators are turned off and the AP
module tests each of the four logic modules, in sequence. (Note: If all indicators re-
main on after the lamp check, the core test could have failed and is unable to turn off
the LEDs.) The self-test diagnostic takes up to 1 minute to complete, during which
time the indicators will turn on and off according to the testing sequence.
If the tests detect a failure in an FRU, that FRU_BAD indicator turns on and the re-
maining modules are tested. This ensures that the fault indicators on each module
will accurately reflect the state of that module, when self-test is complete. If the tests
detect an incompatibility between any of the firmware and the hardware, the
FRU_BAD indicator for that logic module will blink.
If no faults were detected during self-test, the MODE indicator turns on. The bridge
then enters a preforwarding state for approximately 30 seconds, during which time
spanning tree computations are performed and the bridge database is established.
After the preforwarding delay and after the FI connection is established, the state of
the indicators should be as shown in Figure 2–1. (Refer to Chapter 4 for a description
of the indicators.)
