Q: 27" imac wifi problems (intermittant)

Not a dumb question at all. I follow this board and other and have tried all of the solutions (aside from spending more money to give an expensive product the functionaility it was advertised to have). I know of no reasonable solution that does not involve additional expense or giving up on wifi and hooking up by cable. I can say that it does perform better since moving it closer to the router, but this is far from ideal for me.  However, it still underperforms in terms of speed and appears to suffer signal drops (but recovers the signal more quickly). No such problems with other devices. As an added bit of vinegar, I also began suffering frequent losses of connectivity between the "magic" mouse and my iMac. After reading some posts about this new debilitating problem---also disavowed by Apple--I just gave up and plugged a wireless mouse with a usb. No problems. Maybe Apple should just drop its desktop business. Clearly, its attention and resources are focused elsewhere.

Ouch. I suppose the chipset that is doing the wireless mouse is part of the same broadcom chipset family? Apple/Broadcom have a huge problem on their hands and it will explode... best case scenario is people just stop buying Apple products. Worst case scenario, they are liable for years of ignoring and perpetuating the problem. This could turn out to be interesting (especially since a reply to me was just censored) https://discussions.apple.com/message/18988039?ac_cid=tw123456#18988039.

It seems that damage control is in full force. Not a good way to keep customers.

Just got a new rMBP and am having identical problems. terribly frustrating and pretty surprising for a $2000+ machine. Whats worse is that there is no official statement or indication that they accept there is a problem. No fix that I've tried works thus far but you seem like youve nailed down the problem so Im hopeful there is a way to turn off the power management for the wifi in the near future with a patch or something.

May have to just switch to windows 7 for the time being until this clears up. Not ideal as I've had very few problems with OSX in the past and was really looking forward to using it on this new computer.

If you can find a way please let me know, good luck

My solution was to just plug in an ethernet cable. Highly annoying. I have done that since the last time I posted here in early June. That works just fine.

So I've unplugged my ethernet cable just now and I'll see if there's any change in the past nearly two months.

zzzzzzzzzzzzzzzzzz

Judie

I find that I can not put my macbook pro next to iMac27. If I did so, the iMac27 could not connect to the internet. After I have moved the macbook to another room, this problem just disappears!!

But iphone/ipad can not affect the iMac27‘s internet connection!!

And if two machines are working under the windows 7 system, both can connect to the internet without any problems....

Why?????

This is an issue with WiFi... It is interference caused by the two machine using/trying to use the same frequency.

(Note: That is WHAT is happening, not WHY it is happening.)

This is the same reason why other devices operating in the same frequency range (phones, microwaves, etc.) cause problems. The issue is well documented and explained in the 802.11 standard.

Why two WinTel machines don't behave the same way is something I cannot tell you.

Is it an issue with the WiFi (802.11x) software in the iMac? ... that could be. We don't know the answer and to the best of my knowledge, no one with any RF instrumentation has examined the WiFi probem in the 27 inch iMac.

For what it's worth, I just returned moments ago from a coffee house where an entire row of MacBook Pros of various ages were operating adjacent to one another with no apparent problems (and my iPad was on the other side of the room.)

Well, I unplugged the ethernet to my June 2011 21.5" iMac and I've come back to my computer twice and it was offline. It seems every time I go away and it goes into sleep mode or whatever it is then offline when I wake it up. Very annoying. I'll use it like this until either:  a) I have time to take it to the shop for a check up, b) I find my USB wifi thing or c) it drives me too crazy and I just plug the **** ethernet cord back in!  :E

After a lot of frustrations I traded my TP-Link (TL-WR941ND) in for a Apple Airport Extreme and like I was hoping, gone with the issues! I have to be honest, the WiFi drops only occured about a couple of times a weak the last couple of months, but everytime when you least wanted it to.

In retrospect I wish I bought the Airport Extreme to begin with. With an complete Apple machine park (iMac's, MacBook, iPhone's, iPad's) the only thing that could work perfect was an Apple router. Setting up is a breeze like you would expect from an Apple product.

I know this is not a solution for everybody, but mayby to some...

Just to let folks know. Apple Support DOES acknowledge this problem and has several approaches to fixing it. The Tech I spoke with not only knew about the problem, but about the content of this dialog as well!

I DO have an extended warranty on my mid 2010 27inch iMac, and finally got around to calling Apple Support about the Wi-Fi problem (+ Airport Extreme Base Station). I happened to call on a Saturday Moring (EDT) and got a call back within about 30 seconds of entering my request via my still-working iPad!

So far, the first approach worked like a charm. It has now been over 3 weeks and my Wi-Fi connection has not dropped once.

My particular fix involved deleting a set of system level prefences - plist and lock files, multiple reboots (I made the mistake of emptying the trash before rebooting), and then re-configuring my networking.  Sorry, but for the life of me I can't remember which ones (and didn't write them down), and cannot find an apparent "likely culpret" looking at the directory (and creation dates via terminal). Perhaps they were artifacts from Snow Leopard, but I have no idea.

In short. call Apple Support and talk to them. The ideal time to call is when your Wi-Fi connection is NOT working correctly!

THIS FIXED MY PROBLEM IMMEDIATELY AND 100%

I moved apartments yesterday and my ISP offered me a great deal on a new router (vs renting it from them and paying monthly) so I purchased it and began using it today. I had never had any problem with any of the connections on any of my devices before today.

I have a MBP, iPhone, iPad and an iMac. All were working great on the new router except for the iMac which was abysmally slow on Wi-Fi. The ethernet connection was still really fast so I knew there was an issue with the wireless connection.

After trying nearly everything I saw on the internet to fix the problems, my solution was to change my router security from WPA2-PSK [AES] to WPA-PSK [TKIP].

This fix brought my speedtest on my iMac from .3 MBPS to 30 MBPS consistently and have reached 50 MBPS with all of my other devices still working just as well as they were before.

I have given up, I have tried evrything suggested but nothing has provided a long term solution. I have now had my house rewired so that my router is next to my iMac and I can connect a short ethernet cable as the only option. I believe Apple has forsaken us on this issue and may feel that this will not impact on them, they are very much mistaken. There are thousands of iMac user with this problem and I for one will think twice about buying another Apple product or recommending Apple to anyone.  The Apple customer services has been diabolical on this issue.  Apple may be on the crest of a wave at the moment but it is major issue like this one than can ruin reputations.

very angry!

Sorry to hear you've had no luck. What sort of router are you running?

My problem is definitely from my Belkin router. If I run the router in 20MHz mode everything is great (albeit slower than what should be technically possible). If I turn the speed up (to run in combined 20MHz/40MHz mode) my iMac drops on and off the network like there's no tomorrow.

I'd be interested to know if your router uses the same chipset.

Cheers!

Based on recommendations from my internet provider I changed a few months ago from a Belkin to a Thompson. Tiscali advised that they would not support a Belkin router if I encountered any problems. I do not think it is a router problem as many have had the same issue with a vast number of different makes/types. I had a G5 Mac and no wifi problems it is only since I got my new iMac about 12 months ago that I started having problems.  What really annoys me is the fact the Apple are aware there is a problem but do not recognise it publically. I have discussed this issue with sales people from 3 Apple stores and they are all aware there is a problem but Apple choose to do nothing! I am OK now thanks to my ethernet link but I will remember this failure by Apple when I am ready to purchase another tech. product.

I am not sure whether to write this or not. Since installing the latest software update, 2 days ago, I have been able to connect to the internet by wifi. I am not pressing hard on my keyboard unless I jog something which cancels the connection. I believe this latest update included increasing the reliabilty of the connection. I will not be confident of a permanent fix for a couple of weeks as I have had false hopes in the past after trying various ideas from this forum. If Apple have fix this problem that is fanstatic I don't even care that I recently spent £50.00 moving my router closer to me Mac for an ethernet connection.

Maybe  , fingers crossed!

Hello

New poster here. I offer my experience in case it helps others.

I was having problems with wifi dropping regularly usually after sleep mode.

I went through a lot of support calls but the answer came from a visit to the apple store and advice form a genius there.

He suggested it was caused by too many other wireless routers in my locality trying to use the same channel. Apparently the imac doesn't like this and gets confused?

When I clicked on wifi there were about 8 other wireless networks coming up.

He recommended a piece of software called istumbler (free) and this showed the networks were all on the same 'channel'.

I therefore changed the wifi channel to a different one ( I was using a time capsule). I believe there are about 40 or so different channels you can use.

Since doing that I have not had any dropping of the wifi at all.

Many thanks to Simon at apple Solihull or fixing this.

Hope it might help someone else. Good luck.