After 33 months the wireless card on my MacBook started to go really wacky. If it wasn’t within 6-8 feet of a router it wouldn’t do anything. I had AppleCare. At the Apple STore they did a test on continuous throughput and that was fine. I explained it was HTML oriented. We cleared the Safari cache and tried to load pages (20 -30 ft from the router). This illustrated the problem of little, slow or no throughput. They replaced the Airport Card and I had my MacBook the very next day. Internet is flying again from near and far. They also replaced my discolored Keyboard and inside surface as my early model was susceptible to discoloring…which it was. Cudos Apple.
MacBook Airport Card Replaced