I have a toshiba satellite L655D. I did not power it down, just unplugged it and put it in its case. A week later I pulled it out of the case and it would not turn on. Dead battery I guess. I plugged it in and it powers up but the screen is all black. The fan seems to run constantly now. I tried pulling the battery, unplugging and expelling power, but it did not work. Also hooked it up to my tv and the tv says nothing is connected. Any more ideas?
There could be a variety of reasons judging from what you said. Here are what they might be:
1) The computer did not go to sleep when you unplugged and put it in the case. It literally ran so hot in the case afterwards that it cooked (some of) the logic inside, responsible for display and/or more.
2) A coincidence event where the screen died. You can't get it to display via output to TV because you need a special key combination to activate the external display (Fn+something).
It is hard to tell what is the problem until you delve deeper. When you say that it powers up, try shining a bright light on an angle (flashlight) at the screen, can you make out the usual login screen or desktop ?