Lenovo THINKCENTRE 8177 User Manual
Page 66
1.
Turn
off
the
computer
and
disconnect
all
external
devices.
2.
Power-on
the
computer.
3.
There
are
three
LEDs
to
help
you
determine
if
the
power
supply
and
system
board
are
working
correctly.
The
power
button
LED
is
located
on
the
front
of
the
computer
and
the
two
diagnostic
LEDs
are
located
on
the
power
supply
at
the
rear
of
the
computer.
After
pressing
the
power
button,
observe
the
LEDs
and
refer
to
the
following
table:
Power
LED
Green
diagnostic
LED
Yellow
diagnostic
LED
Action
ON
ON
OFF
This
is
the
normal
condition
of
the
LEDs
when
the
power
is
OK.
OFF
OFF
OFF
v
Make
sure
the
power
cord
is
attached
to
a
working
electrical
outlet.
v
Check
the
power
cord
for
continuity.
v
If
the
problem
persists,
replace
the
power
supply.
OFF
(after
the
power
button
has
been
pressed)
ON
OFF
Replace
the
system
board
ON
ON
ON
Replace
the
power
supply
If
the
Diagnostic
LEDs
are
in
the
normal
condition
and
the
problem
persists,
replace
the
system
board
and
the
microprocessor,
one
at
a
time,
until
the
computer
works
correctly.
60
Hardware
Maintenance
Manual