Friends,

My situation
1. I have a dell laptop, its display is gone. Actually there is display, but it is so dim it is impossible to read anything in it.
2. I am using it with my HDTV as an external monitor, and it works fine.
3. OS = Vista 32 bit Home Premium

My problem:
Display comes in HDTV only after windows is loaded (log on screen). I can not get any pre boot display in my HDTV.  Is it possible to change this so that I can get pre booting display?  e.g. if I want to run BIOS setup, i cannot see anything..laptop screen dead, and no display (no signal) in HDTV.


I have tried connecting laptop both with VGA cable, and HDMI cable, but the issue is same.

Any idea will be appreciated.

 Under the display settings you will find a place where you can define your primary display and secondary display. When both displays are connected try changing the primary to the HDTV. This should work, otherwise try getting an updated driver for your display and you'll find the display setting.

 Thanks for reply. But it applies to condition after windows is loaded. I do not get any display before windows is loading. I need to go to BIOS setting (Like we used to press DEL to go in with old normal desktops). 

 Im saying once you define the primary display to hdtv, it should take HDTV it as a primary display next time you reboot, did you check that?

 it did not work...
I am plannning to install windows 7. Only thing I am afraidof is if I am stuck in some sort of problem or menu before windows is loaded, I will never know what happened, and computer will never open...

Some laptops have toggle button to boot on external monitor. Mine is Dell E6400 and I have f8.

Se if also appilies to you

This sounds dumb, but did u try adjusting your brightness using brightness Fn key?
If yes try following
1. Make sure you've not set a power setting that automatically turns down the brightness to a minimum level to save battery power.
2. Shine a flashlight at the screen. If you can see the information on the screen when it's illuminated by the flashlight, then you've probably got a blown backlight. (Havent tried this one yet, lol)
3. if you're OK with a soldering iron and opening up your laptop. Googling "Dell 8600 CCFL" (Cold Cathode Flourescent Lamp) and you'll come across dozens of resources on everything from buying the right $12 replacement backlight, to detailed instructions on how to replace it.

src:http://ask.metafilter.com/88416/Laptop-display-is-suddenly-very-dark

I guess i misread ur question, the issue wasnt the back light but how to get the display on hdtv during setup.

With the external monitor connected, boot into safe mode, then disable the display adapter (in device manager). Reboot (with the external monitor STILL connected), and allow Windows to boot normally. Hopefully, you should now have a display on the external monitor.

src:http://www.computing.net/answers/windows-xp/how-to-make-laptop-boot-to-external-monitor/191776.html

 I think your monitor is gone. As my understanding everything looks great except the brightness of the screen. That means the parts or circuit for the brightness of the screen is gone. What you can do is that you can change the cable that goes to the screen from the laptop. Sometimes that may mulfunctioning. 

It seems like a problem on either LCD cord or LCD itself. You can try to change the LCD cable then LCD if you are familier with it. As you said, your display is gone on the laptop screen and you can see dim on the external monitor (HDTV). You have two options, one is to be fixed by computer repaire stores (BestBuy,Microcenter,computer geeks etc), second, you could try by yourself by googling it. I am pretty sure it's either LCD cable or LCD itself. We had many problems like yours and the company either replaced the LCD cable or LCD itselt.

As my understanding you cant see the initial scree because of the RGB concept, but i am sure there are ways for you to tweak it up.
As for your dim screen, if did not work even after changing changing the display setting...in my opinion there are four reasons:

1) a faulty wire
2) bad inverter
3) bad backlight


If its a inverter and a backlight...its easier to fix.

 Screen is gone, it is inverter problem. I am aware of this.
I can get display in my TV, so cable is good.

My problem is I can not get any display before windows is loaded. I also have a desktop which I have been using same way. With that desktop, I can get pre-boot screen in the TV. That means my HDMi and VGS both are good.

It may be that particulat dell laptop (or may be all, i don't know) are made in such way that we can get display only after OS is loaded (sounds stupid though).

why do you want to see the initial screen...forgive my agroracne...i did not read the other post(dont have time for that)

But if you want to see your BIOS ....

after the windows load up

GO to Rum

TYpe cmd

and on the dos prompt

Type

wmic bios get /format:list

Let me know if its works, if thats what you wanted to do..