3.
Perform
the
following:
a.
Power
off
the
system.
b.
Disconnect
all
the
I/O
devices
(tape,
diskette,
optical,
and
disk
units)
from
the
expansion
unit
or
I/O
tower
you
are
working
on
by
sliding
them
partially
out
of
the
unit
(see
c.
Remove
and
label
all
cards
installed
in
the
PCI
card
area.
d.
Power
on
the
system.
Does
a
power
reference
code
occur?
v
Yes
:
Continue
with
the
next
step.
v
No
:
Go
to
step
10
(See
page
4.
Perform
the
following:
a.
Power
off
the
system.
b.
Remove
one
of
the
air
moving
devices
(AMDs)
from
the
expansion
unit
or
I/O
tower
that
was
not
previously
removed
during
this
procedure.
(Disregard
an
AMD
SRC
if
it
occurs
during
this
step.)
c.
Power
on
the
system.
Does
a
power
reference
code
occur?
v
Yes
:
Continue
with
the
next
step.
v
No
:
The
AMD
you
removed
in
this
step
is
the
failing
item.
This
ends
the
procedure.
5.
Have
you
removed
all
of
the
AMDs
one
at
a
time?
v
No
:
Perform
the
following:
a.
Power
off
the
system.
b.
Install
the
AMD
that
was
removed
in
step
4
(See
page
in
the
original
location.
c.
Repeat
step
4
(See
page
v
Yes
:
Install
all
the
AMDs
and
continue
with
the
next
step.
6.
Perform
the
following:
a.
Power
off
the
system.
b.
Remove
the
expansion
unit
or
I/O
tower
power
supply
cables,
that
was
not
previously
removed
from
one
of
the
DASD
backplanes.
c.
Power
on
the
system.
Does
a
power
reference
code
occur?
v
No
:
The
DASD
backplane
that
was
disconnected
in
this
step
is
the
failing
item.
This
ends
the
procedure.
v
Yes
:
Continue
with
the
next
step.
7.
Have
you
disconnected
the
power
cables
from
each
of
the
DASD
backplanes
one
at
a
time?
v
Yes:
Continue
with
the
next
step.
v
No:
Repeat
step
6
(See
page
8.
Perform
the
following:
a.
Power
off
the
system.
b.
Remove
a
power
supply
that
was
not
previously
removed
and
replace
it
with
the
new
one.
c.
Power
on
the
system.
Does
a
power
reference
code
occur?
v
Yes
:
Continue
with
the
next
step.
v
No
:
The
power
supply
that
was
removed
in
this
step
was
the
failing
item.
This
ends
the
procedure.
Analyze
hardware
problems
173
