The Short Version: The Airlink Wireless N Mini USB Adapter (AWLL6075) works well for an iMac with a broken Airport adapter. The software could be less obtrusive but for the cost (and size of the adapter) it’s a good buy. It doesn’t load until the user is logged in so it can’t be used to connect to network services such as Screen Sharing or File Sharing without first logging in and running the software.
After I upgraded the processor in my iMac from a Core Duo to a Core 2 Duo I discovered that the Airport in the iMac wouldn’t work. The system didn’t show any errors and the card appeared to work, but it couldn’t detect any networks (neither mine nor my neighbors). I opened the system up a few times to see if I could spot the problem and even tried re-seating the card but nothing helped. My best guess is that I may have damaged the antenna.
I didn’t want to run a network cable to the computer, though it can be done. Instead, I started searching for an inexpensive USB wifi adapter on Amazon. It didn’t take long before I found the Airlink Wireless N Mini USB Adapter (AWLL6075). Surprisingly, it was only about $13 but also had good reviews overall. I went ahead and bought it.
So far the adapter seems to work fine. Accessing Internet from the iMac works without any noticeable difference but connecting to Screen Sharing takes longer to initiate. It also has a management program that stays open, which is somewhat annoying but not much.
Some reviewers mentioned they accidentally damaged the included software CD because it wasn’t obvious that one is included in the packaging. If that happens it’s easy to download the driver and application from the Airlink Website.
The adapter’s software worked fine under Snow Leopard and Lion.
Updated 10/26/2011: I haven’t discovered any new problems or quirks. So far, it seems to be working well. Despite its size it manages to pickup the signal at about 99% strength. The router is on the same floor, about half-way across the house with two walls between it and the USB adapter.
Updated 11/04/2011: I’ve realized there is one limitation that I didn’t have when using the Airport. The management program doesn’t load until after I’ve logged into the Mac, which means I can’t initiate a Screen Sharing session unless the account has already been logged in.