Display goes almost dark

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Hi

I have a Toshiba Satellite that is generating a blank display about half
the time.

On boot up or very shortly after that the screen goes almost black - I can
still see very faintly the brightest parts of the screen. On the last power
up it showed the Toshiba banner and the first Windows banner, then went dark.

Nothing seems to bring it back. Usually I just turn it off and then try
again a few hours later. Most of the time it works, some of the time it is
almost black. Other than turning it off I do nothing else that could affect
the display.

This happens when it is plugged in to AC, as well as on battery. The
battery appears fully charged.

I have spent some time with google and not found anything like this. The
laptop is about 2 years old. When it works it works just fine - bright
display, no problems. It may or may not work the next time. Weird.

Brent

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

Brent Beach wrote:
> Hi
>
> I have a Toshiba Satellite that is generating a blank display about
> half the time.
>
> On boot up or very shortly after that the screen goes almost black -
> I can still see very faintly the brightest parts of the screen. On
> the last power up it showed the Toshiba banner and the first Windows
> banner, then went dark.
> Nothing seems to bring it back. Usually I just turn it off and then
> try again a few hours later. Most of the time it works, some of the
> time it is almost black. Other than turning it off I do nothing else
> that could affect the display.
>
> This happens when it is plugged in to AC, as well as on battery. The
> battery appears fully charged.
>
> I have spent some time with google and not found anything like this.
> The laptop is about 2 years old. When it works it works just fine -
> bright display, no problems. It may or may not work the next time.
> Weird.
> Brent

This certainly sounds like a failure in the inverter or a loose
connection in the power circuit connected to the inverter. I do not
believe that it is a problem with the lamp - these can become dim and
off-color, but usually fail outright - not intermittent failures.

You could open the case and check the physical power cable connection to
the mainboard and the power cable as it enters the LCD frame for a break
as a start, but to check the inverter and its connections requires
(usually) the LCD bezel (frame) to be removed. The inverter is
typically located in the space between the hinges at the bottom of the
screen. I've seen inverters on which the high voltage end connected to
the lamp is burned which fails the lamp power supply at that point.

Q

 

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Archived from groups: comp.sys.laptops (More info?)

Quaoar wrote:
> Brent Beach wrote:
>>On boot up or very shortly after that the screen goes almost black -
>>I can still see very faintly the brightest parts of the screen. On
>
> This certainly sounds like a failure in the inverter or a loose
> connection in the power circuit connected to the inverter. I do not
> believe that it is a problem with the lamp - these can become dim and
> off-color, but usually fail outright - not intermittent failures.
>
> You could open the case and check the physical power cable connection to
> the mainboard and the power cable as it enters the LCD frame for a break
> as a start, but to check the inverter and its connections requires
> (usually) the LCD bezel (frame) to be removed. The inverter is
> typically located in the space between the hinges at the bottom of the
> screen. I've seen inverters on which the high voltage end connected to
> the lamp is burned which fails the lamp power supply at that point.

Thanks for the guidance. A loose connection seems like the right answer -
it could be in the wiring that goes through the hinges into the display
since about the only thing I do from one time to the next is open the case!
I will hunt around and see if I can open some stuff up and find out where
the loose connectin is.

Thanks Q

Brent
--
In sunny but cool (0C, perhaps not cool for some) Victoria, B.C., Canada

 

[Guest]

Archived from groups: comp.sys.laptops (More info?)

A followup.

I found a very good site discussing this problem.

http/www.hardwareanalysis.com/content/topic/13841/?o=0

It seems like a lot of people have this problem. Not sure what I put into
google that found it this time but not the last few times I tried.

The site includes descriptions of how to remove the plastic face plate
around the LCD and how to remove and reseat a small connector. My connector
was in fact not fully seated - I guess it has jiggled out over time.

For now, the problem is solved.

Brent

Brent Beach wrote:
> Quaoar wrote:
>
>> Brent Beach wrote:
>>
>>> On boot up or very shortly after that the screen goes almost black -
>>> I can still see very faintly the brightest parts of the screen. On
>>
>>
>> This certainly sounds like a failure in the inverter or a loose
>> connection in the power circuit connected to the inverter. I do not
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Excellent diagnosis!

Brent
--
Victoria, B.C., Canada