Do you have Bluetooth? Wifi and Bluetooth may be on the same card.
If the wifi card is bad, get a cheap usb dongle that works with Mac to quickly get wifi access.
Have you tried running wireless diagnostics to see if it finds anything?
Hold down the option key and press on the wifi icon then you'll see the diagnostics tab in the drop down list along with a lot more detailed information.
It might well find something.
I assume you have another device that can find the wifi networks so you've excluded that half of things.