Laptop only works when plugged in?!

I could really use some help here....
My laptop only stays powered on when it's plugged into the wall, because as soon as I unplug the charger, the screen just goes black even though the battery shows a full charge.
Does anyone happen to know why this might be happening...

Does the entire computer shut down, or does the screen just go black? 😕
Check your settings under "Control Panel > Power Options" to see how your system is configured when it's plugged in.

The screen just goes black, even though the laptop itself seems to be running fine...

Have you checked your power options?

I finally got everything set up! Thanks so much, 🙂
The brightness was just turned all the way down at first... 😵