Lenovo T42/T42P Manual Do Utilizador
LCD-related
symptoms
Important
The
TFT
LCD
for
the
notebook
computer
contains
many
thin-film
transistors
(TFTs).
The
presence
of
a
small
number
of
dots
that
are
missing,
discolored,
or
always
lighted
is
characteristic
of
TFT
LCD
technology,
but
excessive
pixel
problems
can
cause
viewing
concerns.
The
LCD
should
be
replaced
if
the
number
of
missing,
discolored,
or
lighted
dots
in
any
background
is:
v
XGA:
8
or
more
bright
dots,
8
or
more
dark
dots,
or
a
total
of
9
or
more
bright
and
dark
dots.
v
SXGA+:
11
or
more
bright
dots,
13
or
more
dark
dots,
or
a
total
of
16
or
more
bright
and
dark
dots.
v
UXGA:
11
or
more
bright
dots,
16
or
more
dark
dots,
or
a
total
of
16
or
more
bright
and
dark
dots.
Note:
A
bright
dot
means
a
pixel
is
always
on
(white
or
color.)
A
dark
dot
means
a
pixel
is
always
off
(black
color.)
Symptom
or
error
FRU
or
action,
in
sequence
No
beep,
power-on
indicator
on,
and
a
blank
LCD
during
POST.
System
board.
v
LCD
backlight
not
working.
v
LCD
too
dark.
v
LCD
brightness
cannot
be
adjusted.
v
LCD
contrast
cannot
be
adjusted.
1.
Reseat
the
LCD
connectors.
2.
LCD
assembly.
3.
System
board.
v
LCD
screen
unreadable.
v
Characters
missing
pixels.
v
Screen
abnormal.
v
Wrong
color
displayed.
1.
See
important
note
for
“LCD-related
symptoms.”
2.
Reseat
all
LCD
connectors.
3.
LCD
assembly.
4.
System
board.
Horizontal
or
vertical
lines
displayed
on
LCD.
LCD
assembly.
Symptom-to-FRU
index
64
T40/T40p,
T41/T41p,
T42/T42p