Black Screen while in use

[Scarless]

Help. My monitor keeps going black and chimes out while I am working. Is this a Driver issue. My little guy messed with the screen one day. I am afraid he messed up a setting!!??? Or is it hardware issue? This is home computer Dell Windows 7 I believe.
We do have a wireless printer connected and USB mouse. I am not tech term savvy so speak small, easy tech to me please.
Thanks so much

 

[Cycloid Torus]

Turn off all power. Remove all cables and cords. Reconnect all cables and cords. Try power on again. If any beeps except a single chirp, please describe and also tell us what model of Dell you have.