The light is on and still no connection ? What color is the light , it should be green.
If nothing then go into network connections and adaptor settings and see if the wireless adaptor is enabled.
Try plugging a network cable in and see if you can then detect wireless networks? I'm having that problem on a Toshiba laptop...
I finally figured it out. My Laptop has buttons that go across the top of my keyboard. They look just like lights and I was thinking that if something was not working they would not light up. I wiped my finger across them and I heard it beep and discovered they are actually buttons. All I had to do was press the wireless symbol and it turned on my hardware radio switch. Problem solved! It only took me a year to figure that out.