You can call AppleCare today, they're open in the US on Saturdays however because you don't state where you're located I can't vouch for your country.
You can try some fundamentals such as repairing Disk Permissions in Disk Utility, resetting the SMC and resetting the PRAM.
It also could be a simple issue with the DNS settings your ISP is using. Macs can be sensitive to these, if you are not familiar with DNS setting please read MacWorlds DNS Troubleshooting article and then make the follow change:
1. System preferences
3. Click Advanced
4. Click DNS tab
5. Click + sign
6. Add 126.96.36.199
7. Click + sign
8. Add 188.8.131.52
9. Click OK.
10. Exit System Preferences
11. Try out your iMac and report what happened.
I reset smc and pram, alredy tried to repair disk permission (i also reinstalled macosx )
Then I changed DNS and disabled IPV6
I noticed this problem happens 2-5 minutes after the boot
I tried to ping my router without success, but i can see that during pinging in the "network utility" the interface is up with a IP but sent packets are always the same, packets received increase slowly (1 per second). no collisions and no errors in that window
in the "console log" i saw these strange events:
May 7 22:17:12 iMac Apple80211 framework: Scan() error -3905 (Timeout)
May 7 22:17:12 iMacApple80211 framework: __performScan() failed (-3905)
May 7 22:17:24 iMac Apple80211 framework: Scan() error 16 (Resource busy)
May 7 22:17:24 iMac Apple80211 framework: __performScan() EBUSY, sleep 1 sec, try again
May 7 22:17:25 iMac Apple80211 framework: Scan() error 16 (Resource busy)
May 7 22:17:25 iMac Apple80211 framework: __performScan() EBUSY, sleep 1 sec, try again
May 7 22:17:26 iMac Apple80211 framework: Scan() error 16 (Resource busy)
May 7 22:17:26 iMac Apple80211 framework: __performScan() EBUSY, sleep 1 sec, try again
May 7 22:17:27 iMac Apple80211 framework: Scan() error 16 (Resource busy)
and so on…
I had another idea, take a look at the connections sequence in the Network Preference. I've included a picture of mine for an example. If you want the system to be on wi-fi that should be the top choice, if you want it to be Ethernet that should be listed at the top. Believe it or not those aren't random, you can change the sequence by clicking where I've indicated in the graphic and can easily have the order changed.
Hi sander81 - Unfortunately I can't offer much help at this point in time, but I'm experiencing the same problem. My 27" 2011 iMac is frequently losing it's connection from my router. I have 5 other Apple devices (Mac's, iPhone, iPad, Apple TV's) connected to the same router, and no issue with those. If I Turn Off/Turn On the Airport, it magically reconnects, and everything works fine. In 4 hours of using the iMac, it's done it about 6 times so far.
I have the Console open, so if I do see something of interest, I'll let you/others know. Same if I happen to find a resolution to the issue.
thank you for your help
Troy, I have this issue only one time 2-5 minutes after the boot (imac 27'' like you).
Do you use a router 5Ghz (wireless 802.11n) or 2,4 (wireless 802.11g)? I have a linksys e3000 but this problem happens in both configurations. At the end I think could be a driver/firmware problem with the new wireless adapter (with 3 antennas).
If I'll have any news I'll update this thread, thank you
I have a small update. It looks like the issues with the wifi are driver related. I Installed Windows 7 64bit in Bootcamp and tried all kinds of tests there. The network is very stable and no disconnect/connect issues.
What I also discovered is that the room I placed my iMac in is not very well covered by my time capsule. The quality must still be fine as the other devices (macbook air, ipad2, iphone) don't show issues. Maybe it's related to power consumption or something like that.
This is how it looks like. The RSSI should be higher as I understood, but it still should be fine and stable as it works flawlessly in windows.
I have also just purchased a mid 2011 27inch 3.4Ghz i7 iMac and have a Wifi related issue, I orginally connected to an Apple Airport Extreme and all was well, I then put the iMac to sleep, when I woke it up I noticed that web pages in Safari kept timing out, including trying to get to my local ADSL routers admin web page. I then disconnected from the Apple Airport Extreme and re-connected, I still had the same timeout issue. I then disconnected and connected via wireless N to my wireless ADSL router directly, the performance/timeout issue then went away.
I am therefore not sure if this is an issue connecting to the Apple Airport Extreme or any Wirless router, I have not applied the latest firmare update for the Airport Extreme but I have to the iMac.
Not sure if this is related but in another thread I noted that I have also had what are possibly bluetooth issues where there seem to be keyboard and mouse inputs occuring that did not come from the corresponding keyboard or mouse. For example the volume being changed with the on-screen volume bar appearing and in Safari the web pages scrolling down. As I say this may not be related but I would be interested if you are seeing the same issue.
Very interesting Troy, I have DD-WRT like you in my linksys. I'm not at home and I don't remember the version, but should be one of these: ftp://ftp.dd-wrt.com/others/eko/V24-K26/ (or a Branslayer release).
This evening I'll try with another access point or using ad-hoc with another mac
What wireless router do you have ? Have you checked if there is a firmware upgrade for your wireless router ? What version are you using ?
Have you tried updating to 10.6.7 on your iMac ?
Can you also post the details in the kernel panic so someone here with more knowledge might be able to help ?