There are probably other ways to think about this situation, but these are the most likely.
You sit down at the computer, grab the mouse and move it around, but nothing happens.
Without giving you any other information, here are some possible ways to think about this right now:
A. My computer is broken. Someone needs to come help me.
B. The mouse is broken. Someone needs to get me a new mouse.
C. The monitor is turned off. I can't see anything without the monitor turned on. I should turn it on.
D. The computer is turned off. I can't do anything with the computer turned off. I should turn it on.