I had a computer for about a year, and one day it stopped projecting onto my monitor. The computer starts up (even has a light), and stays on, but the screen shows nothing. I've tried multiple cables.

The monitor or the graphics card is bad. Try a different monitor and see if that works. If not, the graphics card is bad in the computer.

If you are able to, try hooking it up to another monitor or TV even and see if it gives you the same problem. If it doesn't, then the new monitor must have some setting or resolution it can't handle coming from the PC.