Hi 711,
If you have one of the F500 series notebooks with an AMD processor, you may be suffering the common problems associated with this series. The AMD cpu runs too hot, causing failure of the Wi-Fi card initially and often leading to failure of the motherboard.
There was a Bios update sometime back, that turned the fan on from startup-that may help. It was some time back I had these problems, so might be good idea to do a Google for latest info. Good luck
richtee.