How do you fix a Wi Fi antenna failure in an Aspire 5742G?

I made the mistake of slapping the lid closed a little too hard (although not violently.) The blue light indicator for the Wi Fi now no longer comes on, and the device drivers for the Wi Fi network card do not load. I replaced the card with a different one from a Lenovo which I know works and loaded the drivers but the system did not recognise it. Does anyone know what part I have damaged and how to replace it? I thought it might be the antenna wires that run up the sides of the screen/lid or the antenna units at the end of them at the top of the screen, but I am not sure if that would affect the blue indicator light or if something nearer the light itself has failed.