Hi I have a Packard Bell Notebook that has been nothing but trouble since we got it.

Recently I shut the screen and opened it again a few moments later and the screen had gone dark black (I could very faintly MAKE out the windows in the background).

Thinking it was the LCD brightness I shut turned it off and re-booted it but when it came back on even the startup (Packard Bell loading screen) was un-readable and dark.

I thought this was the LCD screen failing so I attached it to my other TV and the computer started to boot in full colour until we hit the Vista login user Login screen and then the monitor lost its signal and went black.

So I am left very confused what is causing the PROBLEM?

Any help would be great...Welcome to the Forum.
Somebody will get to you shortly. I want to help, but I am not able. I can not think of anything encouraging to say about a..

Packard Bell Notebook

Sorry. I used to have a laptop screen problem when the LED light (usually at the bottom left of the screen frame) had a short. If you are able to get a full display again by rapidly moving the screen lid, like opening and shutting it fast in succession, or turning it sideways then you know it's the light. You can either try to unscrew the frame then and fix the LED wires or replace it with a new light. There's actually instructions on the net how to do this. If you're not a do-it-yourselfer however a repair shop can fix it for you for a relatively low fee. I the bit that confuses me is it works fine on the seperate monitor as it loads. However when it gets to the vista login screen the other monitor goes "no signal" and reverts back to the laptop and the dark screen again.

I think it may WELL be the LED. can you provide any links to any tutorials or spare LEDS and I will have a go myself.It sounds like your screen's backlight or inverter board (basically, the power supply for the screen) has gone out. Both can be replaced, but require a bit of knowledge about electronics and enough guts to OPEN up the laptop and cut a few wires. If you're not knowledgeable or confident enough with electronics to do this, it's a fairly simple operation for any electronics or computer repair shop.

http://www.laptoprepair101.com/laptop/2007/12/09/replace-laptop-backlight-ccfl-lamp/
http://www.laptoprepair101.com/laptop/2007/01/31/replace-screen-inverter-fix-backlight/Most laptops have the buttons on the keyboard the change the brightness of the display. Normally it’s the up and down arrow keys. You would normally hold down the "Fn" key and tap the up arrow key to make it brighter and the down arrow key to make it darker.My Fn key is not working...my laptop is m9700 alienware.
Is there any other key to resolve this
Perhaps you should start a new TOPIC first....I am inclined to agree with quaxo. If you got it in a good source of light, could you see a faint image of what is supposed to be there? You could also try this:
remove the battery
unplug the ac adapter
press and hold the power button for 30 secs.
leave the battery out, reattach the adapter
power it on normally and let me know what happens.

If you have already tried an ESD, then...it (could) be a software issue.

In that case, I'd recommend backing up your files and performing a destructive recovery to see if that resolves it. If it doesn't, its got to be a backlight issue.