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27" iMac & wireless problem

P

Philinghorn

macrumors newbie
Original poster
Nov 6, 2009
17
0
Hampshire, England
Hello,
I was wondering if anyone has or had the same problem as I seem to have & have any ideas how to solve it.
For about the last month more often than not when my iMac wakes up from sleep the wireless connection doesn't connect to my router. The signal bar is either on max or 1 down from max, but it hasn't connect to my router (all other computers in my house can connect, so I think the problem lies with the iMac). Safari won't get to the internet (or routers admin page), Mail won't send or receive mail, & no replies to a ping command. The only way I have found to get it working is to turn off Airport & then turn it back on, all is fine then until it goes back to sleep. I have tried giving the iMac a static ip address as well as being on DHCP, but no difference.
If someone can help I would be very grateful (Wife & kids would also be very happy.)
All updates are current, running osx 10.6.3 on a 27" iMac.

Thank you for any advice.

Phil
 
I would suggest you to delete your network from the preferred networks list on your Mac. In Network Preferences, select AirPort, and start out by turning off the AirPort card. Then click Advanced, select the first tab in the overlaid window. Remove your network using the - sign, click Ok, then Apply. With AirPort still off, go to Keychain Access, delete the password for your network. Restart the computer, turn AirPort back on, rejoin your network and authenticate. Put the computer to sleep from :apple: or using Hot Corners, wait 5-10 minutes, maybe 30 or overnight, and wake it back up. Does it work?

I would also suggest, as a long shot, I'll admit, checking for a firmware update for your router, especially if the 27" is the only "new" computer in your household that is having these problems.

Just another side thought, you don't have a dual-band router do you? Try renaming the secondary band. Your iMac may have trouble rejoining the n or g network if both are active and are named the same...
 
Thank you JediMeister for your quick reply.
I have done as you suggest regarding turning off the AirPort card & the keychain etc & so far so good.
I will post back & let you know how I got on.

Thanks once again.

Phil
 
Hello,
It stop again this morning :( as I was surfing the net the pages stop loading & times out & the ping command to my router timed out. So it looks like its not a wake issue.

I don't think it can be a firmware issue with the router as it has been working for 3 years, and faultless with my iMac up till about a month ago.

I don't believe the router is a dual band, its a Netgear DG834GT supplied by Sky (my isp) using Sky's own firmware.

Thanks for any thoughts

Phil
 
Same problems

I have a 21.5" and am having the same problems. I've been wading through logs, changing firewall setting, etc. for more than a month and the problem seems to be getting worse.

No wireless problem the first 3 or 4 months. We first noticed a problem a couple months ago, surfing using safari or firefox and the connection would just quit working even though the airport thought it was still connected. Disabling/Enabling worked so didn't think much of it. I noticed the last couple of Updates for snow leopard had airport items in it and so I was always hoping the problem would go away.

What started as a weekly thing is now several times a day. Even worse a new symptom just started where the connection doesn't drop entirely but the connection speed drops to 2k. Disabling/Enabling doesn't fix it but several hours later the problem clears.

BTW - I have a macbook running leopard with zero problems and always faster internet connection sitting on the same desk. (Leaving snow leopard disk in plastic wrap until this is resolved)

My next steps are to manually assign an IP address and disable iTunes from accepting inbound requests (lose remote functionality but small price).

I am currently connecting it Linksys Wireless G router. So I may upgrade firmware, etc. next if I can't resolve soon.

Another interesting side note - installed chrome on both macbook and iMac over the weekend. No problems on Macbook (10.5) but crashes/times-out constantly on iMac (10.6) to the point it is un-usable on the iMac.
 
RE;27" iMac & wireless problem

It seems that the Apple’s new Intel machines have some issues with wireless LANs using WPA/TKIP. Users have reported that switching from WPA/TKIP to no encryption (not recommended!) or to WPA2/AES fixed their wireless connectivity problem. Since I have configured my wireless router and my iMac to use WPA2 with AES, i.e. “WPA2-Personal”, everything is working fine and as expected.I hope you like my suggestion im sure they will work proper way
 
Just for reference, I've seen EXACTLY this behavior on my 2006 MacBook Pro running 10.4, 10.5, and 10.6 connected via G to an AEBS (both UFO model and Gigabit N model), once or twice on a brand new 27" iMac connected to the same Gigabit AEBS via N wireless, and at my parents' house a 2009 Mini running 10.6 connected via G to a G-only Netgear router.

The problem was drastically improved between 10.4 and 10.5, but I STILL see it every once in a while (maybe once a week or so, with a lot of wake/sleep cycles). Interestingly, 10.6 appears to accurately identify it, anyway; while earlier OSes would show full bars, 10.6 shows a ! mark, indicating a problem. Except the only way to get it to connect is still to turn Airport off and back on.

In my case while 10.4 also had some dropped connection problems that I narrowed down to interference from another router, under 10.5 and up the problems are exclusively limited to waking the computer--I've never had it go out while doing something (other than the rare occasion when the router actually hangs, requiring a power cycle to kick back in; that's happened a couple of times and is a completely different issue).

Point being that this is a somewhat endemic problem. It's obviously not universal, or I assume it'd be fixed by now and you'd read about it more here, but none of the things I've tried to date (channel, change position, interference robustness, hardware resets, deleting network and recreating it, removing keychain entries, firmware updates) have helped.

If anybody does manage to get the flake-on-wake issue fixed, I'd love to hear about it.
 
Hello Back again !
I seem to have got my AirPort working, I hope I don't speak too soon but it has been OK for for the past 30Hrs+.
I went back & checked the Keychain Access & found the password for my router was in twice, once under "login" & again under "system". They both had different modified dates - I know I had previously deleted & setup again as per
JediMeister but the date in system was for a few months ago (when my problems started ?). I followed JediMeisters instructions again making sure I deleted all references to my router.
As of now OK:D
So maybe the fault is due to Keychain some how confusing the router log on/access. There is a now difference when the iMac wakes, the AirPort signal strength icon "light up" 1 bar at a time until its connected.

Thank you JediMeister & I hope it works for other people.

Phil
 
Airport Express Icon Missing And Not In Network List

I am connecting wirelessly to my time capsule though when I commence airport utility. I don't think I have ever had an airport icon in the top menu bar ever since I bought my i7 imac 2 months ago. Should I do a reinstall of mac os or any other ideas??? Apple are saying I have to send it back to them and pay the freight as I am 800km away from a store and I do not want to do that with a 2 month old expensive imac. When I go to network airport is not listed there either. Will a reinstall of os wipe my data?
 
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