Laptop display all white

"Jerry West" wrote in message
...
Negative. The moment the power comes on the display is all white and
remains so. Works others wise, i.e. accessible via network. But kinda
useless otherwise.

JW

"Brian Cryer" not.here@localhost wrote in message
...
"Jerry West" wrote in message
...
I have a Dell Inspiron 8600 with a Mobility Radeon 9600 Pro Turbo card in
it. The other day it suddenly had the display turn all white. All the
white pixels are on and showing. That's it. It works fine otherwise, i.e.
I can reach it thru the network but alas, it is basically useless like
this. I tried replacing the video card in it but that did not fix the
issue.

If you power it off and then back on again do you see the BIOS messages
and does it go all white when it hits windows? IF that is the case then
its probably the display driver which is at fault. I had this problem
with an old laptop, it was fine unless I allowed windows update to pull
down an update to the display driver and then all I got was a white
screen. The solution in my case was to boot into vga mode (F8 at startup
should give you that option), uninstall the display driver and replace it
with the original that came with the laptop.
--
Brian Cryer
www.cryer.co.uk/brian

Hello,

Sorry to jump into the conversation so late, but I thought I'd add my
thought about the lcd display. If it's all white, then it's not likely the
backlight in the lcd. That's good because the backlight is not a simple
replacement. I think instead that it might be the inverter. That's a
simple replacement and the inverter for your laptop is probably available in
the listings for your model on eBay for about $10 or $15 or so. That would
be what I would try. Dollars to donuts that if you get a picture on an
external display and have an all white LCD, it's the inverter. HTH, JG

With all due respect, you are really displaying a serious lack of
knowledge of how displays work.

If EITHER the actual backlight lamp or the inverter is bad, the display
will stay completely dark. It will look like the laptop was never even
turned on. A white display means that BOTH the backlight lamp and the
inverter are good.

jfg wrote:


Hello,

Sorry to jump into the conversation so late, but I thought I'd add my
thought about the lcd display. If it's all white, then it's not likely the
backlight in the lcd. That's good because the backlight is not a simple
replacement. I think instead that it might be the inverter. That's a
simple replacement and the inverter for your laptop is probably available in
the listings for your model on eBay for about $10 or $15 or so. That would
be what I would try. Dollars to donuts that if you get a picture on an
external display and have an all white LCD, it's the inverter. HTH, JG

Barry Watzman wrote:
With all due respect, you are really displaying a serious lack of
knowledge of how displays work.

If EITHER the actual backlight lamp or the inverter is bad, the display
will stay completely dark. It will look like the laptop was never even
turned on. A white display means that BOTH the backlight lamp and the
inverter are good.

jfg wrote:


Hello,

Sorry to jump into the conversation so late, but I thought I'd add my
thought about the lcd display. If it's all white, then it's not
likely the backlight in the lcd. That's good because the backlight is
not a simple replacement. I think instead that it might be the
inverter. That's a simple replacement and the inverter for your
laptop is probably available in the listings for your model on eBay
for about $10 or $15 or so. That would be what I would try. Dollars
to donuts that if you get a picture on an external display and have an
all white LCD, it's the inverter. HTH, JG


Interesting. But what is wrong then in the OP's machine?

--
John Doue

In ,
John Doue typed on Sat, 05 Dec 2009 23:18:09 +0200:
Barry Watzman wrote:
With all due respect, you are really displaying a serious lack of
knowledge of how displays work.

If EITHER the actual backlight lamp or the inverter is bad, the
display will stay completely dark. It will look like the laptop was
never even turned on. A white display means that BOTH the backlight
lamp and the inverter are good.

jfg wrote:


Hello,

Sorry to jump into the conversation so late, but I thought I'd add
my thought about the lcd display. If it's all white, then it's not
likely the backlight in the lcd. That's good because the backlight
is not a simple replacement. I think instead that it might be the
inverter. That's a simple replacement and the inverter for your
laptop is probably available in the listings for your model on eBay
for about $10 or $15 or so. That would be what I would try. Dollars
to donuts that if you get a picture on an external display
and have an all white LCD, it's the inverter. HTH, JG

Interesting. But what is wrong then in the OP's machine?

Video card (aka motherboard), cable, or the display itself.

--
Bill
Gateway MX6124 ('06 era) - Windows XP SP2

John Doue wrote:


Interesting. But what is wrong then in the OP's machine?


My take on this.

With some LCD display types, a 'panel bias voltage' is required to be
supplied to the LCD assembly. This effects both viewing angle and
contrast of the display, and is often a negative voltage having to be
generated by a special circuit linked to controls on the laptop that
alters contrast for the user. If no voltage supplied, then no contrast.

It's going to be the cable or the panel. Unless if that negative bias
voltage is also generated by the parts on the inverter board - then it
could be the inverter board itself. Or, failing that, the mainboard. I
dunno to give an exact forecast.

Knowledge of the beast is required. Best find a shop that is pulling
these laptops apart regulary that is having access to spares and dead
carcasses to do substitution tests.

--
Adrian C

[Composite Reply, to several, non-linearly-connected replies.]
++++++++++++++++++++++++++++
Jerry West wrote:
Somewhere on teh intarwebs Barry Watzman wrote:
I have a Dell Inspiron 8600 with a Mobility Radeon 9600 Pro Turbo
card in it. The other day it suddenly had the display turn all
white. All the white pixels are on and showing. That's it. It works
fine otherwise, i.e. I can reach it thru the network but alas, it is
basically useless like this. I tried replacing the video card in it
but that did not fix the issue.
Anybody know what else I should check? Is it toast?

You tried replacing the video card? VERY FEW laptops have video cards
(although a number of Dell models do).

The Dell 8600 *does* have a replacable graphics card, completely different
to the system that Alienware uses though:

http://www.bay-wolf.com/8500video.htm
http://neodon.blogspot.com/2006/06/d...utopsy_29.html

(The second link shows a 'broken' graphics card but, if the OP's test card
that he fitted was a known good one [was it Jerry?] then we can likely rule
out that.)
++++++++++++++++++++++++++++++
Somewhere on teh intarwebs Jef Roe wrote:
If it works on and external monitor then it most probably is the
paned or cable. You might find a panel with backlight and cable on
ebay for little money.

Here is the second red herring. It seems that most read this and assumed
that it meant that the laptop *does* work with an external monitor.
++++++++++++++++++++++++++++++
Somewhere on teh intarwebs BillW50 wrote:
In ,
John Doue typed on Sat, 05 Dec 2009 23:18:09 +0200:
Barry Watzman wrote:
jfg wrote:
[top-posting fixed]
Hello,

Sorry to jump into the conversation so late, but I thought I'd add
my thought about the lcd display. If it's all white, then it's not
likely the backlight in the lcd. That's good because the backlight
is not a simple replacement. I think instead that it might be the
inverter. That's a simple replacement and the inverter for your
laptop is probably available in the listings for your model on eBay
for about $10 or $15 or so. That would be what I would try.
Dollars to donuts that if you get a picture on an external display
and have an all white LCD, it's the inverter. HTH, JG

With all due respect, you are really displaying a serious lack of
knowledge of how displays work.

If EITHER the actual backlight lamp or the inverter is bad, the
display will stay completely dark. It will look like the laptop was
never even turned on. A white display means that BOTH the backlight
lamp and the inverter are good.

Totally agree.

Interesting. But what is wrong then in the OP's machine?

Video card (aka motherboard), cable, or the display itself.

As you can see above, it's not "video card (aka motherboard)" at all. GIGO.

There could be a clue in this Wikipedia article:

http://en.wikipedia.org/wiki/Dell_In...ne_LCD_problem

Maybe in this case the 'vertcal line' comprises the whole screen?
--
Shaun.

"Give a man a fire and he's warm for the day. But set fire to him and he's
warm for the rest of his life." Terry Pratchet, 'Jingo'.

See my previous post on the subject. There are 3 possible causes. But
neither the inverter nor the actual backlight lamp is any one of those
three.


John Doue wrote:
Barry Watzman wrote:
With all due respect, you are really displaying a serious lack of
knowledge of how displays work.

If EITHER the actual backlight lamp or the inverter is bad, the
display will stay completely dark. It will look like the laptop was
never even turned on. A white display means that BOTH the backlight
lamp and the inverter are good.

jfg wrote:


Hello,

Sorry to jump into the conversation so late, but I thought I'd add my
thought about the lcd display. If it's all white, then it's not
likely the backlight in the lcd. That's good because the backlight
is not a simple replacement. I think instead that it might be the
inverter. That's a simple replacement and the inverter for your
laptop is probably available in the listings for your model on eBay
for about $10 or $15 or so. That would be what I would try. Dollars
to donuts that if you get a picture on an external display and have
an all white LCD, it's the inverter. HTH, JG


Interesting. But what is wrong then in the OP's machine?

No, wrong.

There is NO connection between the inverter board of any laptop and the
LCD panel other than the lamp.

And your whole dissertation about bias voltages relates only to DSTN
type panels, which have not been used in any laptops for approximately 7
years.

Your statement that it's the panel or the cable is simply wrong (not to
say that it could not be either of them, but rather that the video
circuitry, whether it's on the motherboard or a separate video card, is
a 3rd possibility).

There are a lot of people commenting on this situation who simply do not
know what they are talking about.


Adrian C wrote:
John Doue wrote:


Interesting. But what is wrong then in the OP's machine?


My take on this.

With some LCD display types, a 'panel bias voltage' is required to be
supplied to the LCD assembly. This effects both viewing angle and
contrast of the display, and is often a negative voltage having to be
generated by a special circuit linked to controls on the laptop that
alters contrast for the user. If no voltage supplied, then no contrast.

It's going to be the cable or the panel. Unless if that negative bias
voltage is also generated by the parts on the inverter board - then it
could be the inverter board itself. Or, failing that, the mainboard. I
dunno to give an exact forecast.

Knowledge of the beast is required. Best find a shop that is pulling
these laptops apart regulary that is having access to spares and dead
carcasses to do substitution tests.

Somewhere on teh intarwebs Barry Watzman wrote:
No, wrong.

There is NO connection between the inverter board of any laptop and
the LCD panel other than the lamp.

And your whole dissertation about bias voltages relates only to DSTN
type panels, which have not been used in any laptops for
approximately 7 years.

Your statement that it's the panel or the cable is simply wrong (not
to say that it could not be either of them, but rather that the video
circuitry, whether it's on the motherboard or a separate video card,
is a 3rd possibility).

There are a lot of people commenting on this situation who simply do
not know what they are talking about.

Agreed.
--
Shaun.

"Give a man a fire and he's warm for the day. But set fire to him and he's
warm for the rest of his life." Terry Pratchet, 'Jingo'.

Adrian C wrote:
John Doue wrote:


Interesting. But what is wrong then in the OP's machine?


My take on this.

With some LCD display types, a 'panel bias voltage' is required to be
supplied to the LCD assembly. This effects both viewing angle and
contrast of the display, and is often a negative voltage having to be
generated by a special circuit linked to controls on the laptop that
alters contrast for the user. If no voltage supplied, then no
contrast. It's going to be the cable or the panel. Unless if that
negative bias
voltage is also generated by the parts on the inverter board - then
it could be the inverter board itself. Or, failing that, the
mainboard. I dunno to give an exact forecast.

Knowledge of the beast is required. Best find a shop that is pulling
these laptops apart regulary that is having access to spares and dead
carcasses to do substitution tests.

Barry Watzman wrote:
No, wrong.

There is NO connection between the inverter board of any laptop and the
LCD panel other than the lamp.

Thinkpad T20-T23?

And your whole dissertation about bias voltages relates only to DSTN
type panels, which have not been used in any laptops for approximately 7
years.

TFT panels do have a bias supply as well. As I said, it could be on the
panel.


--
Adrian C