User Manual
ADCP-75-150 • Preliminary Issue A • March 2003 • Section 5: Maintenance
Page 5-15
©
2003,
ADC
Telecommunications,
Inc.
5.3 Host Unit Fan Replacement Procedure
The
HU
is
equipped
with
two
cooling
fans
which
are
located
on
the
right
side
of
the
HU
enclosure.
The
cooling
fans
blow
cool
air
into
the
enclosure.
Heated
air
is
exhausted
through
the
vent
openings
on
the
left
side
of
the
enclosure.
Replacement
of
the
fans
requires
that
the
HU
be
turned
off
for
a
short
period
of
time.
Use
the
following
procedure
to
remove
and
replace
the
HU
cooling
fans:
1. Before
working
on
the
HU
or
handling
a
fan,
slip
on
an
Electro-Static
Discharge
(ESD)
wrist
strap
and
connect
the
ground
wire
to
an
earth
ground
source.
Wear
the
ESD
wrist
strap
while
completing
each
section
of
the
fan
installation
procedure.
2. Notify
the
NOC
or
alarm
monitoring
system
operator
that
the
system
is
going
offline.
3. Place
the
HU
On/Off
switch
in
the
OFF
position
(press
O).
4. Remove
the
six
flat-head
screws
(requires
TORX
screwdriver
with
T10
bit)
that
secure
the
fan/grill
assembly
to
the
right
side
of
the
HU
enclosure
as
shown
in
Figure 5-2.
Save
screws
for
reuse.
Figure 5-2. Host Unit Fan/Grill Assembly Removal
5. Carefully
withdraw
the
fan/grill
assembly
from
the
enclosure
until
the
wiring
harness
is
exposed
and
the
connectors
are
accessible.
6. Lift
the
small
latch
on
each
wiring
harness
connector
and
carefully
unplug
each
connector
from
the
circuit
board
connector.
7. Remove
the
plastic
rivets
that
secure
each
fan
to
the
grill
by
pushing
outward
on
the
rivet
center
post
until
the
rivet
can
be
withdrawn
from
the
grill
as
shown
in
Figure 5-3.
Warning:
Electronic
components
can
be
damaged
by
static
electrical
discharge.
To
prevent
ESD
damage,
always
wear
an
ESD
wrist
strap
when
working
on
the
HU,
STM,
or
LPA
and
when
handling
electronic
components.
16986-A