iMac struggles with WiFi

[philipm]

I have a reasonably new iMac that I bought in Australia about a year back before moving back to SA and it really battles with WiFi. I thought the Linksys box I was given here may be faulty so I swapped it out for a Billion (both ADSL + ethernet + WiFi), and it's no better. I'm sitting right next to the iMac with a Macbook and WiFi works just fine on it.

Any ideas?

Putting in wired ethernet would be a good plan but not easy the way the house is constructed.

 

[JStrike]

You might have a faulty airport card. I'd take it in to DigiCape or an iStore. It has a worldwide warranty

 

[Zyzzyva]

Lion introduced a few wifi issues on a number of macs. Even with the updates, which did fix a couple issues, lion has been a bit of a dogs breakfast for many people when it comes to wifi. Its hit or miss really. As a rule though, you always want buy routers with broadcom chips as most macs use broadcom. It can help.

 

[[)roi(]]

I have a reasonably new iMac that I bought in Australia about a year back before moving back to SA and it really battles with WiFi. I thought the Linksys box I was given here may be faulty so I swapped it out for a Billion (both ADSL + ethernet + WiFi), and it's no better. I'm sitting right next to the iMac with a Macbook and WiFi works just fine on it.

Any ideas?

Putting in wired ethernet would be a good plan but not easy the way the house is constructed.

Some WiFI authentication types can give problems with different devices -- I suggest you google up on this.

 

[vinodh]

The only problem I had with Wifi on my MacBook Pro was when I update Lion to 10.7.2. Every time I opened the macbook, it woke from sleep and asked to authenticate the wifi connection. I tried various tricks with power saving etc and nothing worked. I eventually deleted all the network connections, restarted it and created a new wifi connection. Its been working fine since.

A fresh install can also help. I really hope its software and not hardware related.

 

[Zyzzyva]

The only problem I had with Wifi on my MacBook Pro was when I update Lion to 10.7.2. Every time I opened the macbook, it woke from sleep and asked to authenticate the wifi connection. I tried various tricks with power saving etc and nothing worked. I eventually deleted all the network connections, restarted it and created a new wifi connection. Its been working fine since.

A fresh install can also help. I really hope its software and not hardware related.

Turning off bluetooth was also a fix for that problem oddly enough.

 

[philipm]

You might have a faulty airport card. I'd take it in to DigiCape or an iStore. It has a worldwide warranty

I'm not sure about that but I'll check if I'm not out of warranty and see if I can buy AppleCare.

For those mentioning Lion: this is with Snow Leopard. Before I moved here I had the iMac mostly on ethernet but other things I had on WiFi worked OK. I switched back from the Linksys box I was using to the Billion that was OK in Brisbane, and it's not a whole lot better (its behaviour seems more consistent and doesn't seem to need hard reboots as much, but reception is patchy).

I'm wondering if I would do better to put the router in the ceiling space. The ceilings are made of wood but that may block RF a bit less than thick brick walls.

 

[philipm]

Turning off bluetooth was also a fix for that problem oddly enough.

Bluetooth and WiFi share the 2.4Ghz spectrum space and theoretically are meant to play nicely but at one point I found that if I had a Bluetooth device switched on near the iMac, throughput collapsed. With no Bluetooth devices near, I was seeing 4Mb/s throughput on ADSL download; with, a fraction of that. Not supposed to happen but it was one of the most repeatable experiments in my attempt at tracking down the problem. I'm back to USB keyboard and mouse on the iMac, but it's no better on the whole (just works better when it can make a connection).

 

[bwana]

I'm not sure about that but I'll check if I'm not out of warranty and see if I can buy AppleCare.

For those mentioning Lion: this is with Snow Leopard. Before I moved here I had the iMac mostly on ethernet but other things I had on WiFi worked OK. I switched back from the Linksys box I was using to the Billion that was OK in Brisbane, and it's not a whole lot better (its behaviour seems more consistent and doesn't seem to need hard reboots as much, but reception is patchy).

I'm wondering if I would do better to put the router in the ceiling space. The ceilings are made of wood but that may block RF a bit less than thick brick walls.

I recall having a lot more wifi problems with SL than I do currently with Lion. Perhaps it's time to make the switch?

You could also try switching channels? BTW - if you hold down the option key while clicking on the wifi icon in the menu bar you'll get additional info that might help.

 

[[)roi(]]

Bluetooth and WiFi share the 2.4Ghz spectrum space and theoretically are meant to play nicely but at one point I found that if I had a Bluetooth device switched on near the iMac, throughput collapsed. With no Bluetooth devices near, I was seeing 4Mb/s throughput on ADSL download; with, a fraction of that. Not supposed to happen but it was one of the most repeatable experiments in my attempt at tracking down the problem. I'm back to USB keyboard and mouse on the iMac, but it's no better on the whole (just works better when it can make a connection).

If you can't see the network or consistently fail to connect -- then try a different authentication type and check protocol support 802.11a/b/g/n?

If it connects but intermittently fails then you most likely have an interference issue; the 2.4Ghz spectrum is utilized by a number of devices so interference is quite probable -- you can try the following:
1. Download an App called iStumbler -- it will help you to see all the WIFI networks around you and to identify any conflicting networks and open channels.
2. Unplug any custom wireless devices; for example I had a lot of problem from a wireless transmitter / receiver I was using to relay TV signals -- Although it had Icasa clearance, I would experience countless issues when it was switched on.
3. Invest in a better WIFI router -- e.g. One that can also simultaneously operate in the 5Ghz band (Apple, Cisco, ...)

Fyi I tried a few devices Linksys (Cisco home / non commercial devices), Billion, TP-Link, Huawei, ... I was setting up a WIFi network for my mom -- I had a lot of intermittent failures and many of the 2.4Ghz devices would intermittently work (rebooting the router appeared to be the only solution that worked) -- lest to say I returned all routers. All my issues were resolve when I installed an Apple Airport Extreme router (operates simultaneously on 2.4Ghz and 5Ghz bands)

 

[PAYBACK]

I had the some issues with my Airport as well. Constantly having to log in out of the blue. This worked for me. Untick "Remember any networks this computer has joined" in the advanced options. See if that helps. I've had no issues since unticking that box.