Power
supply
LED
errors
Use
the
power
supply
LED
information
on
the
following
page
to

troubleshoot

power
supply

problems.

Note:

The
minimum

configuration

required

for
the

DC

Good

LED
to

come

on

is:

v
Power
supply
v

Top

power

board

AC
good
LED
DC
good
LED
Front
power
on
light
Power
good
indicators
(midplane)
Description
FRU/action
Off
Off
Off
Off
No
power
to
system
or
ac
problem.
1.
Check
ac
power
to
system.
2.
Power
supply.
3.
Top
power
board.
On
Off
Off
Off
DC
source
power
problem
Unplug
the
three
power
connectors
to
the
midplane
board.
If
the
DC
Good
LED
does
not
come
on:
1.
Inspect
and
replace
any
damaged
power
cables.
2.
Check
ac
power
to
system.
3.
Power
supply.
4.
Top
power
board.
On
On
Blinking
Off
Standby
power
problem
1.
Disconnect
the
following
items
from
the
midplane
board
to
isolate
the
failing
FRU:
a.
Light
Path
cable
and
SCSI
power
cable
b.
Memory-board
assembly
c.
Processor-board
assembly
d.
PCI
or
PCI-X
adapters
e.
PCI-X
board
f.
Remote
Supervisor
Adapter
(watch
for
lit
or
flashing
LEDs
on
I/O
board)
g.
I/O
board
cable
attachments
2.
If
LEDs
are
on
after
removal,
replace
the
offending
device.
3.
If
no
LEDs
are
lit
after
step
1,
replace
the
following:
a.
I/O
board
b.
Midplane
board
On
On
On
Off
Failure
to
power
up
POWER
GOOD
problem
1.
Check
indicators
for
a
failing
VRM;
replace
any
failing
VRMs.
2.
Remove
the
adapters
and
disconnect
cables
and
power
connectors
to
all
internal
and
external
devices.
Turn
on
the
server.
3.
If
the
Power
Good
LED
comes
on,
replace
the
adapters
and
devices
one
at
a
time
until
you
isolate
the
problem.
4.
Power
supply.
5.
Top
power
board.
6.
Midplane
board.
On
On
On
On
Power
is
OK.
N/A
180
IBM
xSeries
450
Type
8688:
Hardware
Maintenance
Manual
and
Troubleshooting
Guide