2–10
DECbridge 500/600 Problem Solving
Table 2–1 (Cont.): Problem Solving Via the LEDs
Symptom
Probable Cause
Corrective Actions
All LEDs are off (cont.).
Bad fan or
Remove ac power for at least 15 seconds, then
overtemperature
reapply. If LEDs work properly for a few minutes,
condition
then all turn off again, replace the fan assembly.
Defective module
Remove NI, FI, and QM modules. Rerun self-test
and check LEDs on the AP module.
If AP LEDs are OK, replace other modules (one
at a time) and retest each time until the defective
module is identified. Replace the defective module.
If the AP LEDs remain off when only the AP module
is in the unit, replace the AP module and retest.
Defective power
If the LEDs still remain off after all previous
supply
actions have been taken, replace the power supply
(Section 3.3.4).
All LEDs remain on.
Core test failure
Replace the AP module (Section 3.3.2).
AP_BAD, NI_BAD,
Module connections Reseat all the logic modules in their connectors.
FI_BAD, QM_BAD
all remain on.
AP module failed
Replace the AP module (Section 3.3.2).
Bad backplane
Replace the backplane (Section 3.3.6).
AP_BAD, NI_BAD,
Improper upgrade
Return the unit to its original configuration.
FI_BAD, QM_BAD
all blinking.
AP/AP2 Module LEDs:
AP_BAD remains on.
AP module failed
Replace the AP module (Section 3.3.2).
self-test diagnostic
NVRAM error
Reset module to factory defaults (switch 2).
AP_BAD blinking.
Incompatible
Replace the AP module with one containing a
firmware loaded
compatible firmware revision (Section 3.3.2).
