Do you have a VGA socket? Then you can try a monitor to that and if that works it is probably your screen. If it also show on a remote screen it is probably the graphics hardware - could mean a new motherboard.
It is not a Toshiba by any chance is it?
I don't think Toshiba's are especially prone to this problem any more so than other laptops.
Between the main part of the computer and the screen there is a flexible connector. Over time, the connections on ANY laptop flexible connector can degrade and eventually fail. Or the screen can get damaged during transit.
The test suggested is, however, sound and will diagnose whether there is a system problem or a flexible connector/screen problem.