Bottom line: my WIFI problem was fixed after I replaced the cable connecting my wireless card to the motherboard!!!
Although the the causes of the problems can vary depending on each specific case, I suspect that many people had the same problem as mine!
Keep reading to find out more details.
Like many of the folks who came to this forum, I had the WIFI not working problem for almost half a year! Here were my symptoms:
- At the beginning, my WIFI would suddenly stop working after awaken from sleep, the WIFI icon on my Macbook Pro became empty without any bars. The wifi would not restore no matter what I try, unless I restart my laptop. After a few days, the WIFI would stopping working in the same way even when it was not sleeping.
- After have had this problem for a while, I started to see the "Hardware not installed" problem. Sometimes a reboot would solve the problem, sometimes it couldn't. Many folks attribute this to a software or OS problem, but to me, since my WIFI would suddenly stopping working while everything else was normal, it seemed more like a hardware problem. The "Hardware not installed" message was also supporting my guess.
- Nonetheless, I tried everything I could to solve the problem, including lots of software- or OS-wise resttings. None of them really worked. Some of them seemed to work after retbooting, but it was unclear if those were due to the reboot it self or not.
Finally, I happened to read some posts regarding the WIFI cable that was connecting to my motherboard and the wireless card. Several people got the problem fixed after replacing the cable. But as many had pointed out, this could be due to either the cable, or the wifi card. I therefore tested my wireless card while it was functioning, by opening my macbook pro while it was running, and carefully disconnecting the wireless antennas and the wireless cable one by one. It turned out that I only lost my wifi when the wireless cable was disconnected; WIFI signal was weak but existent when all antennas were disconnected. This was the same too my bluetooth as well, despite that my bluetooth never had any problems. So after those tests, it appeared to me that it was my cable that was causing the WIFI problem, especially the "Wireless card not installed" problem.
So after so much frustrations with different types of wifi USB dongles (none was compatible with 801.1X enterprise authentication), I decided to replace the wireless card cable. I bought one replacement cable from eBay, and followed the instructions on iFixit.com. After replacing the cable, my wifi was recovered and I have not had any problems for 3 months since then!
So bottomline: it is very likely a loose cable issue rather than a software issue for most people. Replace your wireless cable or, in a worse scenario, your wireless card, then you will likely solve the problem.
Good luck everyone!
