I am now experiencing this issue. I am using a mid 2012 macbook pro and up until yesterday I havent had a problem.
I did all the basic checks on my router, Skys piece of crap SR101, and im still getting intermittent wifi issues. After seeing my son stream seamlessly on his tablet and xbox, as well as trying wifi on my desktop, i can definitely rule out any issues with the router. i also jacked into the router via ethernet and it worked flawlessly.
At this moment in time, web pages (via safari) are loading ok but like i say, the problem seems to be intermittent and VERY annoying. I did suspect last night it has somthing to do with my mbp hence why i have started looking through threads like this.
I run a retina MBP from June 2012 and have had this problem very intermittently for the past few months or so. I shrugged it off since it was so random and because the wifi would usually spring back relatively quickly. In the past week it's escalated to the point that I lose my wifi within 5 minutes of logging on, almost guaranteed. Pinging a website will not keep it up. The only way to get wifi working again is to log out and log back in or reboot...at which point it will last a few minutes then crap out again.
The only reason I'm NOT completely sure it's a problem with my airport card is the fact that internet works FINE when I log in as "Guest" instead of my main account on the laptop. I've literally been logging in and out b/w my account and the Guest account in order to use internet and it is one of THE most frustrating issues I've ever dealt with on a computer of any kind. This is ridiculous.
I've reset my SMC, PRAM, deleted everything in my networks preferences, cleared my keychain, and wiped the SystemPreferences folder, and none of those have fixed this issue. I'm quite ticked at this point.
I just started looking here today because my MBP (about 5 yrs old) running 10.8.5 just lost all wireless connectivity yesterday. I've actually been having problems for several months now where my or my wife's MBP (hers is 2 yrs old, same OS) just lost internet access though the wireless appeared to be connected. I found that if I went to her MBP, which was often asleep, and asked it to check email, it would first complain of no internet then be successful on the second try. Mine would then work just fine. Over the last several months this has become more frequent, often several times an hour. We've actually had issues (maybe every week or so) before this of losing internet and found that resetting the WAP/router fixed it. Then we started getting this apparent interference issue where waking up one computer seemed to fis it.
Yesterday, though, my MBP lost wireles completely. The wireless icon at the top was just the open triangle with no bars at all. When I asked to search for networks I couldn't find any, even though I usually see 6-8 of my neighbor's networks. And, I could see them on my wife's MBP. I rebooted several times, tried turning the wifi on and off, but to no avail. Wired ethernet worked fine.
Today I found this article and laurenmay1's suggestion about deleting the files. I did that and upon rebooting it came back up (after I turned the wifi on). I could see the neighbor's networks and was able to connect up to mine (it's hidden). So, we'll see how long this works, but it looks promising!
Well, this didn't really work. I did get my wireless turned back on but then it started dropping out again after a couple of days. I replaced my WAP/router today and everything seemed to be working. Until I rebooted my MBP. Back to not being able to see ANY wireless networks anywhere. Tried deleting the files again and that didn't work!
Wired Ethernet wtill works but I haven't been able to get my wireless turned back on. The WAP/router is still working fine for my wife.
OK. I have been holding my breath wanting to say something, but did not want to jinx anything. For about a week my WiFi worked as it use to, just fine in many environments jumping on and off networks as it should and use to. I just pretended that all was well and perish the thought that there was a problems. All I did was one day got fed up and dumped all network connections and started from scratch with one WiFi. No joy. Then added Ethernet, because I needed to connect. Still no WiFi. Then for the heck of it I added a VPN, not set up, and waddya know I got WiFi and as I said it lasted for about a week. Then as quick as it came, it went away. I tried the same exercise and no joy. But I had it and it was just fine for about a week. So . . . this, adding to the echo, is a real Cluster Frack.
I searched for a few hours and went to the genius bar and my problem was not going away. I couldn't let it go before I took a second trip to the genius bar and I came accross your post. I did both the deleting the passwords for Airport in Keychain and repaired disk files. I thought it didn't work but I only restarted instead of turning off and turning on again. This morning I woke up and wala my internet is back. I think it was the deleting of the passwords in Keychain because the disk repair list had nothing about airport in there. So, thanks a super bunch for posting that. Previous attemps to fix included clearing cache, resetting Safari, messing with network settings (IP, DHN or whatever those things are), deleting and re-creating Airport, deleting system pref files, and lastly holding commmand, option, P, and R on startup. I was going to take two more trips to the genius bar and then call Apple Corporate Customer Relations. I am so happy this is fixed!!!!! Thanks again!
Going to post this again - since I HAVE NOT LOST THE CONNECTION IN WEEKS AND WEEKS.
After reading some of the recent posts, there may be an additional file to delete, but here is what worked for me and others - again thanks to 2dutch):
Here it is:
Open Finder and navigate to this directory:
Delete these files:
Another me too, but my experience seems a little different. I started getting sporatic internet connections on my iMac about a week ago but the solution was to turn off airport then turn it back on. (All the while, my old MBPro is working fine.) That worked for a while but I'd get less and less internet time each time I rebooted airport. Skip ahead to today where now airport doesn't even find my network and in fact, it doesn't find any of the roughly 15 networks in my apartment complex. Now it finds 1-2, always the same ones. Anyone else out there like me?
I've tried deleting the keychain passwords, changing channels, renaming my network, repairing disk files, and most of the other solves in this thread. So far, no luck.
The guy did not know what the problem was so he gave me some things to do until I could come back. He said it may take more than one appointment. He created a test user to see if that would work, had me try Google Chrome to see if was Safari, and he had me logging Pings while on the Internet so to see what the messages are when I am disconnected.
I did all of the above and more. Changed the router multiple times, changed the chanel, changed the keychains passwords, had my house rewired inside and out. Went to genius bar multiple times, created new user, erased EVERYTHING and reinstalled, got Google Chrome. NOTHING NOTHING NOTHING.
Until I implemented the big fix - the recommendations of 2Dutch which I posted above. No problems since.
Before the big fix, I noticed when I stayed connected to Netflix, I didn't lose the connection for about 12 hours.
I believe MOST of the problems we are experiencing can be allieviated by deleting files - but you may need to find if additional ones are necessary for you.
Note my troubles started after installing a new operating system in 2010/2011. All 3 laptops had the same problem. I suffered for well over a year before getting the big fix. If it doesn't work for you, please focus your efforts in this area. Good luck. Lauren