Dead Airport Extreme card?

Question

For the last three days I have had issues with my G5 dual 2GHz and OS X 10.4.2, the latest updates to Airport software and firmware.
The signal strength meter in the menu bar or in Internet Connect is greyed out and the connection cannot be made -- eventually it gets to the point where the G5 cannot even remember any of my precvious connections. The Macwireless.com widget shows the connection and signal strength as bouncing from 0 to about 70% for all connections that are still recognized, with each location bouncing from the top of the list to the bottom and then sometimes disappearing altogether. After a short while the locations don't reappear... Once they're gone, they're pretty much gone without a trace (Airport Admin either cannot connect to the Airport, telling me an error occurred while trying to access it, or it doesn't see anything to get an error message from).
My G4 sits right next to the G5 and has shown no problems. Strangely, after a full day trying to troubleshoot this, the G5 started up today at full signal strength -- I'm using it now to write this message! Nothing has changed on this machine in the past week, except for me trying to get the Airport Extreme Card to function as it had for the month or two I've had it. Yesterday I lost connection altogether -- neither restarting the Mac nor a full shut down, wait a minute or two, restart would restore my connection. At one point, I shut down the machine for about an hour while I reseated the AE Card and let the computer become room temp (roughly 70 F). Still no go...
After eliminating all the variables I could think of, I've come to the conclusion that the Airport card is probably bad -- possibly malfunctioning with heat build-up (?). Problem is, how do I show this problem to a tech? Especially since it's a half-hour drive to the closest Apple store and longer to a third-party Apple repair shop. And knowing that once it's been off for a while and is on a workbench, it will behave like all intermittently faulty equipment and work perfectly. :-/
If anyone has trouble shooting suggestions, or can help me determine for sure that the card is the problem, please help!

Answer 1

Hi Julia,
Well, the card may have problems too, but I now think there's a software problem as others have suggested. It's odd because everything seemed fine for some time after applying the updates, so it appeared as if the card was bad or going bad. For me, I spent three days trying everything I could, including removing and re-seating the card, antenna wire and antenna, trying various configurations, resetting the Airport itself and so on. All to no avail.
On the last day, I had the strangest situation, where Mail could not see the Airport and could connect to nothing, but Safari was able to access the Internet! I used Safari to access sites I hadn't visited in months just to be sure I wasn't seeing cached versions of the pages... Eventually though, Safari lost contact, and that was it for the day.
After all that, the next day I turned on the Mac to see a solid connection that's been stable ever since except for the incident in my previous post where the Airport widgets knocked the connection out. Turning off those Widgets and closing Dashboard brought the connection back up immediately -- I haven't tried them again, and probably won't!.
Once I had the solid connection, I used Onyx to repair permissions, optimise the System and to empty the Network cache. I also deleted the various Locations I'd set up in the Network Preferences to get it back to just the one connection to choose from. If you're comfortable with Onyx (or Cocktail or one of the other utilities) you could try at least clearing the cache(s) and repairing permissions.
Have you tried a complete shut down and leaving the computer off overnight? Do you have anything set to open on startup that may try to connect with the Internet (like Mail or Safari)? Try removng them from your Startup Items (you can do this from the Dock -- click and hold on the icon and a mini menu should pop up with that option).
Have you looked at the info in System Profiler, and does it show the Airport card? (you can access System Profiler from the About This Mac item in the Apple Menu and clicking the button: More Info...) The card should show up under Network>Airpport Card.
Since you have a Powerbook, you have the option to take your computer to an Apple tech (Apple Genius at an Apple store, or to a dealer with a repair crew) and have them troubleshoot it. My guess is they'll end up reinstalling your OS and/or replacing the card... My G5 is far too heavy for me to throw it in the car -- and I found out the hard way yesterday that my computer is just 2 weeks out of warranty, so I'm ineligible for AppleCare. grrr... (my fault, but grrr...)
Let us know if anything good happens -- best of luck!