Unable to connect to Wi-Fi network "The Wi-Fi network " " could not be joined."

[ManoaHi]

A new router will probably work. But first this sounds like you have MAC address filtering turned on and have not registered this iMac into the router. That it connects up with the Apple Store right away and they don't enable MAC address filtering. I can't check right now, but also check the Windows MAC address. I understand the same hardware, but I've seen this happen on my Nook Tablet. I have the N2A and the MAC address was different from the standard Nook tablet MAC address, yet using the same hardware. It was driving me nuts as our neighbor has no password on their router (I've since helped them enable the password) and I was able to connect to their router, but not mine. Then on a whim I checked the MAC address while on N2A and found there was a different MAC address from the stock Nook MAC address. Just a thought.

 

[mad_macs]

Different OSX version?

Unfortunately, the router is only single-band (2.4Ghz only), so I don't have the option to try and alternative frequency. I have changed the channel of the router, but this does not seem to have had an effect.

Following additional troubleshooting steps suggested here: http://www.igeeksblog.com/how-to-fix-wi-fi-issues-in-mac-os-x-el-capitan/ I have managed to connect to the Wi-Fi by creating a new location, DNS entries and manually altering the MTU. Although this has got me connected, I am still suffering with terrible latency and packet loss and attempting to load any website results in a download speed akin to a 28.8Kb/s modem .

Does this help somewhat?

I ran into a similar problem many years ago with a compatibility issue with a OS driver connecting with certain types of fax machines. It was subtle enough to make a connection but not finish a handshake. When it did connect it would garble the transmission. Backdating the OS actually improved the communications and allow successful connections and transmissions. Is your iMac too new to run say Mavericks (I'm guessing Yosemite to similar to El Cap) for testing? It seems you've run through just about everything except sniffing the packet output. My thinking is that if this works on Mavericks it's a compatibility issue with the router/OSX version and might deem a bug report.

 

[Convert2008]

As I read the thread, you are using wireless only and not wired Ethernet plus Wi-Fi. (I have had problems with both being connected to the same router.) I would turn the iMac off. Reboot the router. Turn on the iMac. Go into System Preferences>Network and create a new profile. You can use Assist Me, and give it a new name. Also, since the iMac is not portable, do not have it search for new networks. Another option is to turn off the Firewall in System Preferences>Security, then turn it on after you are connected. Good luck.

 

[magnat2]

Evening all,

My first time on these forums, so hoping someone could offer some assistance with this issue.

I have a 2015 iMac with 5K Retina Display that is experiencing a curious fault. It is currently unable to connect to my home Wi-Fi network and displays the following message whenever I try and connect:

"The Wi-Fi network " " could not be joined.
Try moving closer to the wireless router. Alternatively run Wireless Diagnostics to troubleshoot."

The iMac is in a location with a strong Wi-Fi signal and all other devices within the same location can connect to this SSID (including the MacBook Pro on the same desk as the iMac on which I am typing this). I have used Wi-Fi explorer to troubleshoot, and can see no issues with the strength of the network, interference from other channels etc.

I have tried deleting the SSID from KeyChain, and then re-connecting from scratch to no avail. I took the iMac into the Genius Bar but when tested, it connected immediately to the in-store Wi-Fi without any issue. I also have a separate Windows 10 Bootcamp partition which can connect to the same network without any issue, which would seem to rule out hardware. The only thing that they could suggest following my own triage, was to re-install OSX which I did, and which did appear to fix the issue. Upon a subsequent boot-up of the system however, the fault has re-occurred again.

I am an experienced IT Support Engineer with a strong Windows background (still making the full adjustment to Mac), and am at a complete loss to explain this behaviour. Clearly, this is not hardware else the Windows partition would also have issues and I could not connect to other networks. Likewise, this is clearly not 100% software, as the iMac can connect to all other networks tested. Finally, this is clearly not 100% a router issue, as every other device in the house can connect without issue including other MacBook's, iPhone's etc.

I suspect that some corruption has taken place deep within a config file that is then being cached for this SSID specifically, however I have not been able to evidence this, and likewise would have expected the re-install of OSX to resolve this type of fault.

Can anyone offer any other suggestions for where to go with troubleshooting this issue?

Regards,

gdthreepwood

Manually define your iMac's IP, I am almost sure your problem will be over. If not try changing your routers operating channel.

 

[danipoak]

This sounds eerily similar to an issue I had with a MBA and it wound up taking a couple years to resolve. It would connect to every network except my home network. I fixed the problem by using a USB dongle for a long time. Eventually I noticed that if I moved within about 5 feet of the router (Airport Express or Extreme) I would be able to access internet via the internal card. Every time I took the computer into the Apple store WiFi worked though and the couldn't diagnose it. Eventually with some time the MBA couldn't connect to hardly any networks and finally someone recognized that it was either the airport card or the antenna (which was built into the monitor). I replaced the airport card since that was a cheap easy fix but it didn't work. Finally it was sent off and they replaced the screen (which replaced the antenna) and now everything works.

One suggestion I have that might help diagnose it more quickly is take your router into the Apple store along with the computer. They can plug ethernet into the router and then set your computer up some distance away from it that approximates your setup at home and see if you can replicate the problem that way.

 

[pjhutch]

Do you have other devices that could internfere with your 2.4 band wifi. That could stop any connections to it unless you are really close to the wireless.
I have a Wifi Analyzer app on my phone so I can see what other wifi connections there are and view signal strength.
As Jake says, switching to a 5 GHz band would help as that would eliminate common interference sources. Onthe wireless you could change the channel number it operates on, to change the frequency range: https://en.wikipedia.org/wiki/List_of_WLAN_channels .

For now I would use wired connections to the Mac.

 

[Garry Anderson]

Try Different Router Hardware

I recommend you try WiFi connection to an "AirPort" router (express or extreme). In my experience, they are the most reliable. I have seen these types problems before with Cisco and Linksys routers. From now on, I only use "Air Port" routers.

 

[Garry Anderson]

I recommend you try an Apple "Air Port" router (either express or extreme) for a test. I have seen these types of problems with Cisco and Linksys routers before. Now, I only use AirPort routers.

 

[Alex 3]

Some older routers are not automatically compatible with new systems. I have seen this before.
Also, in terms of products the iMac based on friend's experience that Apple has not fixed after nearly 2 yr of ownership seems to be a bit flakey.
The fact that other devices connect is probably good in that it demonstrates the router is functional with them and the fact that when on an ethernet connection it connects makes me more suspicious there is potentially a compatabilty with your router.
Do you have access to a more modern router at a friends or at work where you can take it and see if it connects? If it doesn't there then I would take the thing back and ask for a replacement.

 

[pbw]

This sounds eerily similar to an issue I had with a MBA and it wound up taking a couple years to resolve. It would connect to every network except my home network. I fixed the problem by using a USB dongle for a long time. Eventually I noticed that if I moved within about 5 feet of the router (Airport Express or Extreme) I would be able to access internet via the internal card. Every time I took the computer into the Apple store WiFi worked though and the couldn't diagnose it. Eventually with some time the MBA couldn't connect to hardly any networks and finally someone recognized that it was either the airport card or the antenna (which was built into the monitor). I replaced the airport card since that was a cheap easy fix but it didn't work. Finally it was sent off and they replaced the screen (which replaced the antenna) and now everything works.

One suggestion I have that might help diagnose it more quickly is take your router into the Apple store along with the computer. They can plug ethernet into the router and then set your computer up some distance away from it that approximates your setup at home and see if you can replicate the problem that way.

This is the first suggestion I have seen that the problem is with the Mac, which is what I have thought after reading all of the above. If your router is working with your other MBP and with your other wi-fi devices, then it's working, full stop. What happens when you set upa wi-fo hotspot on your phone, and try to connect to that?

As for the Apple Store, most of the "geniuses" are barely competent, and they just go through the normal channels. If you are very lucky, you will find one who 1) actually wants to solve your problem, and 2) has a manager who supports him. Good luck finding that combination. You will just have to keep *****ing and moaning until they decide that it's worth spending the time to fix your problem.

Use twitter and facebook (pardon me while I pause to regain my composure) to complain as well. That generally gets a more concerned response.

 

[danipoak]

This is the first suggestion I have seen that the problem is with the Mac, which is what I have thought after reading all of the above. If your router is working with your other MBP and with your other wi-fi devices, then it's working, full stop. What happens when you set upa wi-fo hotspot on your phone, and try to connect to that?

As for the Apple Store, most of the "geniuses" are barely competent, and they just go through the normal channels. If you are very lucky, you will find one who 1) actually wants to solve your problem, and 2) has a manager who supports him. Good luck finding that combination. You will just have to keep *****ing and moaning until they decide that it's worth spending the time to fix your problem.

Use twitter and facebook (pardon me while I pause to regain my composure) to complain as well. That generally gets a more concerned response.

Your experience with "geniuses" has also somewhat been mine. I was lucky in that when the antenna started getting worse I found one that recognized it pretty quickly. Unfortunately it was out of warranty and didn't have the cash to send it off then. I year later I did. The genius I got that time didn't think anything was wrong but armed with the right information I could direct him to the problem. That's the unfortunate part is to get warranty repair you pretty much have to go through them. So, armed with the right information OP should be able to get it fixed if the problem is with the mac.

Something else I thought to look for that could be a sign of a bad antenna is what is your IP address? Is it self assigned or an IPV6 address? That was one of the problems I had and when I would get within a few feet of the router i would get a normal IP address. It wasn't like that every time though. Sometimes I would have a normal IP address but just no internet.

 

[MacInWin]

Given that the WiFi router only has a single band, I suspect it's getting long in the tooth and needs replacing. The one time the iMac used a different WiFi router, it worked perfectly (the test in the store). Never mind that other systems connect, they may also be hanging on by a thread to a weak router as well. So, buy (or borrow) another wifi router and see if the iMac can attach IN THE HOME, not the store. That's about the only way to find out if it's the router or the iMac. If the new one works, it's the router. If it doesn't, then the problem is most likely in the iMac. Until you know which is the case, we're not likely to get a solution for you.

But try not to go aggressive on the store. Nice actually works more often. And definitely don't take the issue to the social media, that will get ugly in a heartbeat and won't help the case at all.

 

[Nji8sjshg7s]

Have you try a WI-FI USB adapter? I didn't see in any of the posts this suggestion.
If it works then it is the OS and the wireless card.

I think you have tried Mavericks.

If you can remove your SSD drive and place a new one. If it is large enough make several partitions and install Lion (if it is possible) then ML, all the rest.
Then you can try to connect wirelessly with all these OS and find out who works if any.

 

[matey3]

It sounds like a hardware defect, Maybe a problem with the internal wifi antenna...
Sorry if that was already suggested? I only read the 1st page...