Have you accidentally switched it over to an external screen mode?
If you're getting a signal on another monitor when plugging it in, this is the most likely option. On my Satellite the key combo to do it is Fn+F5 - pressing it toggles the mode on & off. If yours is different, look on the function keys (top row) for a logo that has a little picture of a computer, then a slash, then a screen.
Hope this helps.
If you're getting a signal on another monitor when plugging it in, this is the most likely option. On my Satellite the key combo to do it is Fn+F5 - pressing it toggles the mode on & off. If yours is different, look on the function keys (top row) for a logo that has a little picture of a computer, then a slash, then a screen.
Hope this helps.