dell latitude c840; Display issue

[nikyyy]

i own a dell latitude c840 notebook with a 32 MB nVidia GeForce4 440 Go video card. recently, the screen became fuzzy with lines and it started getting worse. it seems that it works when i restart the computer and reboot it with vga mode. even then, the lines do appear and then stop after a while and that is when i can refresh the screen and make them go away. But, a slight touch of the computer makes the lines reappear thus causing the laptop to automatically reboot. My question is: is this a result of a malfunctioning video card, or can it be something else? if it is from the video card, can i replace it with the same one or even upgrade to the compatible 64 mb card, or is it impossible to change the vid card on this particular notebook?

Thank You.

[Yoob@NBF]

C840 is business class version of the Inspiron 8000, 8100, 8200 which had a common problem of the flex cable failing. miraculously the rest of the notebook is extremely sturdy. To ensure the part in question is the issue it would be a tremendous amount of help if you could plug in your notebook into an external screen to see if you an recreate the problem so we can strike out other parts being the problem such as the videocard. If it so happens the videocard is not the issue then we can assume its the infamous flex cable problem which is a cheap fix probabaly 10-30 dollar fix froma part you can find pretty easily online on froogle.com or ebay.com.