4–6
DECbridge 500/600 Series Problem Solving
4.2.3
Indicators
The LED indicators are located on the four logic modules and are visible from out-
side the unit. In general, green LEDs indicate the presence of power and show the
state of each port; red LEDs indicate a fault; and yellow LEDs indicate the presence
of activity on a communications link.
When the bridge is first powered on (ac power cord plugged in), all LEDs light mo-
mentarily to check the indicators. Once this lamp check is complete, the self-test
diagnostics turn the LEDs off or leave them on according to the testing sequence. The
functions of all LEDs in the DECbridge 500/600 series are described in Table 4–2.
Table 4–2:
LED Indicators
LED
Symbol
Color Normal Description
AP
2
or AP Module:
AP BAD
Red
Off
On
--
Self-test failed
Off
-- Self-test passed
Blink
-- Incompatible
firmware loaded
FAN BAD
Red
Off
On
-- Fan failure
Off
-- Fan OK
MODE
Green
On
On
--
Bridge operational
Off
--
Self-test in progress
Blink
--
Down-line load
in progress
DC OK
Green
On
On
-- DC power OK
Off
-- DC power failure
QM Module:
QM BAD
Red
Off
On
--
Self-test failed
Off
--
Self-test passed
Blink
--
Incompatible firmware loaded
