User Manual
ADCP-75-150 • Preliminary Issue A • March 2003 • Section 5: Maintenance
Page 5-6
©
2003,
ADC
Telecommunications,
Inc.
During
normal
HU
operation,
all
LED’s
should
be
green
except
the
STANDBY
LED
which
should
be
Off.
When
a
Minor
alarm
occurs,
one
or
more
of
the
LED’s
will
turn
yellow.
When
a
Major
alarm
occurs,
one
or
more
of
the
LED’s
will
turn
red.
It
is
recommended
that
whenever
there
are
multiple
alarms,
the
optical
alarms
should
be
checked
and
cleared
first.
Because
the
host
and
remote
units
function
as
a
system,
a
fault
in
the
fiber
optic
link
will
cause
various
unit
alarms
to
be
reported.
Table 5-6. Remote Unit Minor Alarms
MINOR ALARM LED INDICATOR MINOR ALARM LED INDICATOR
Temperature STM Sec
Laser
Fail (Does
not
apply)
Sec
Rev
Mux
Lock (Does
not
apply) Sec
Rev
Synth
Lock (Does
not
apply)
Rev
Path
Level (Does
not
apply) LPA
Disable STATUS
(LPA)
LPA
Fan PA LPA
High
Temp PA
Minor
Extern
Alarm
Inp (Does
not
apply) RF
Out
Ve r y
Low (Does
not
apply)
Table 5-7. Host Unit Fault Isolation and Troubleshooting
LED: POWER Color: Off Alarm Type: Major
PROBLEM: The HU is not powered.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1.
The
fuse
is
open
or
removed
from
the
fuse
panel.
1.
Replace
or
reinstall
fuse
at
fuse
panel.
LED: STANDBY Color: Green (blinking) or
Yellow (blinking)
Alarm Type: None
PROBLEM: The HU is out of service.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1.
The
HU
is
in
the
standby
(green)
or
program
load
(yellow)
mode.
1.
Use
DEMS
to
place
the
HU
in
the
normal
(off)
mode.
LED: HOST UNIT Color: Yellow Alarm Type: Minor
PROBLEM: The HU is overheating.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1.
Air
intake
or
exhaust
opening
to
HU
chassis
is
blocked
2.
Ambient
temperature
>>
50º
C/122º
F.
3.
Faulty
fan.
1.
Remove
cause
of
air-flow
blockage.
2.
Reduce
ambient
temperature.
3.
Replace
HU
fan
(See
Section
5.3).
LED: HOST UNIT Color: Red Alarm Type: Major
PROBLEM: A major alarm fault detected by HU.
POSSIBLE CAUSE CORRECTIVE ACTION/COMMENTS
1.
Fiber
optic
link
fault.
2.
HU
and
STM
band
mismatch.
3.
The
HU
has
failed.
1.
Follow
procedure
specified
when
the
PORT
1/
PORT
2
LED
is
red.
2.
Replace
HU
or
STM
with
correct
unit.
3.
Replace
the
HU.