blank notebook screen after installing Samsung 245bw

HELP my notebook screen went blank after installing Samsung 245bw (dual display - XP) on a Sony VGN-A790, 17”, 1920x1200, ATI 600x (256MB) graphics card. Samsung 245bw was replacing ViewSonic 21' (1600x1200) as dual monitor after the ViewSonic primary screen went out after 2 years.

Has any notebook users reported problems using Samsung 245bw as dual monitor, ATI 600x mobility card, Sony notebooks, &/or using digital cables, etc.???

Samsung & Sony restrict & consider online support as offering updates & drivers without problem solving for consumers. Both refer consumers to "phone support" after online & website can’t solve new product problems Both provide excellently consistent customer phone support & problem resolution with their on-hold & hang-up program. Sorry about that, my monitor is still blank but I feel a little better. ?-) AMD-ATI website states there is a problem connecting dual monitors to notebooks with DVI cables (I used analog) but no solution exists ?!!?

The blank screen is really VERY DARK & can be barely read with a fluorescent lamp inches away from the screen. No brightness or contrast control. The Samsung works as the primary or shared desktop with my primary occasionally flickering on startup showing Tinkerbelle is inside & alive? I have tried everything short of reformatting the hard drive & reloading XP which is difficult with a blank monitor.

Experienced help appreciated. This is difficult being disabled, dependent on my notebook & unable to use phone as primary communication. Time & expense points to a new computer. A few forums indicated similar problems involving voltage demands?
I'd appreciate suggestions, thanks rafdo