I have a HUGE problem with my toshiba... I needed to restart it because of some updates, so I did.... And after that, nothing happened... It just appeared a black screen, i turned it off, and on again and nothing, not even the "Toshiba" logo... If I press f12 or f2 nothing happens and eventually sounds a *Beeep* (That sounds like the one you hear when you overload the keyboard).... If I press Ctrl+Alt+Delete the screen turns off and then on again.
Fan works fine... CD-ROM sounds fine, all Battery, AC and Processor lights work fine....
It's ominous that the Toshiba logo doesn't appear. This might be a motherboard problem that costs more to fix than buying a new laptop.
The one thing you can try is to remove the memory cards and try them one at a time. Sometimes a failed memory card can cause this problem.
Just be sure that you don't touch the metal contacts on the cards.