New imac 2015 27 5k will not automatically link to router after sleep

Question

New imac 2015 27 5k will not automatically link to router after sleep

We have the following hardware and OS in our house

2013 Airbook 13" OS 10.6.8 (snow leopard)

2013 Macbook Pro 15" El Capitan up to date

2009 imac 27 i7 El Capitan up to date

2015 imac 27 5k i7 El capitan up to date

Ipad on IOS 8

Iphone 6s plus IOS 9

Iphone 5s on IOS 9

The 'Advanced' network settings on all of the computers are the same (except for the IP address that is gained from the router by DHCP)

All computers except for the 2015 imac automatically link to internet from shut down or sleep.

On the Imac 2015:

I have reset SMC, PRAM, All internet and wireless settings after binning the airport plist file then reboot.

I have tried auto DHCP, manual DHCP, Total manual input and still the 2015 imac will not automatically connect from sleep

It is in the same room as the older 2013 imac used to be. The wifi signal level is full bars. The router is fine and has been tested (it also is doing fine with all other computers and iphones....

So the problem seems to sit with the new imac or the airport software.....but I would love to hear if there is a solution that actually works...I seem to have tried them all!

Posted on Feb 14, 2016 7:18 AM

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Answer 1

Linc Davis

Level 10

209,547 points

Feb 14, 2016 7:37 AM in response to Mike Gilchrist

The warranty entitles you to complimentary phone support for the first 90 days of ownership.

If you bought the product in the U.S. directly from Apple (not from a reseller), you have 14 days from the date of delivery in which to exchange or return it for a refund. In other countries, the return policy may be different. If you bought from a reseller, its return policy applies.

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Answer 2

dialabrain

Level 10

122,525 points

Feb 14, 2016 7:45 AM in response to Mike Gilchrist

FWIW, my 5k has no problems connecting after sleep. In Network preferences, a few things to try is, disable "Ask to join new networks", set Location to "Automatic" and in "Advanced", delete any networks in the "Preferred Networks" list other than the one you connect to.

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Answer 3

Feb 14, 2016 8:39 AM in response to Linc Davis

'linc davis' I am in UK and it was bought directly from Apple but over 14 days ago. The 90 day phone support only tell me to do what I have dome already.

'dialabrain' The settings are already as you have mentioned

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Answer 4

Linc Davis

Level 10

209,547 points

Feb 14, 2016 8:48 AM in response to Mike Gilchrist

Please test after taking each of the following steps that you haven't already tried. Stop when the problem is resolved. Back up all data before making any changes.

1. If possible, test on at least one other network, such as a public hotspot or the hotspot created by a mobile phone. Some Wi-Fi routers are not fully compatible with some Apple devices.

2. Make sure the network is on the preferred list by following these instructions. It's important to read the article carefully, as it's the starting point for any further efforts to solve the problem. If you skip any of the steps, the problem may not be solved. Make sure the box marked

Remember networks this computer has joined

is checked.

3. Follow the applicable instructions in this support article.

4. Reset the PRAM.

5. Make a note of all your settings for Wi-Fi in the Network preference pane, then delete the connection from the connection list and recreate it with the same settings. You do this by clicking the plus-sign icon below the connection list, and selecting Wi-Fi as the interface in the sheet that opens. Select Join other network from the Network Name menu, then select your network. Enter the password when prompted and save it in the keychain.

6. From the Location menu at the top of the Network preference pane, select Edit Locations. A sheet will drop down. Click the plus-sign button to create a new location. Give it any name you want. In the new location, set up the Wi-Fi service with the same settings you used before. Click Apply and test.

7. Launch the Keychain Access application. Search for and delete all AirPort network password items that refer to the network. Make a note of the password first.

8. Repair permissions on the startup volume.

9. Turn off Bluetoothand test.

10. Reset the System Management Controller.

11. This step shouldn't be necessary, but has been advised by Apple Support in some cases, apparently as a workaround for a bug. Open the Energy Saver pane in System Preferences. If applicable, click the padlock icon in the lower left corner to unlock the settings. Enter your administrator login password when prompted.

Select the Power Adapter tab and uncheck the boxes marked

Wake for Wi-Fi network access

and

Enable Power Nap...

if present. Then, if the computer is a MacBook, select the Battery tab and uncheck

Enable Power Nap...

12. Reinstall OS X.

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Answer 5

Feb 14, 2016 9:49 AM in response to Linc Davis

Hi Linc Davis

I have already done the steps that you indicated, as you posted this sequence in answer to another similar problem so time ago and I followed it before posting my problem on the forum.

If you see in my first post...we have multiple computers/devices on the wifi network (I forgot to include in the list; 2 Apple TVs and one airport express) and all of them perform exactly as they should except for the brand new iMac.

As I said all the wifi network settings on all of the computers are the same except for the IP addresses.

The older 27 inch 2009 imac was used to screen share with the macbook-pro so that it could be controlled from the macbook pro. It was also the computer streamer for Homeshare.

The new 5k i7 iMac has taken over that service now as being the computer controlled/screen shared by the macbook-pro and also the computer that streams iTunes content to the Apple TVs.

It is not that it can't link to the router, it is just that it does not do it automatically after being woken....... and it also will occasionally drop the homeshare signal while streaming during a movie to the Apple TVs and needs the wifi in 'network preferences' to be turned off and then on again and the router to be reselected to be able continue homeshare and the movie. ............Sometimes I have to reboot the Apple TV, the router and the 5k iMac to get the homeshare back up.

I can only surmise that the airport system (hardware or software) in the 2015 5k i7 4ghz iMac is not completely compatible with the BT router as it is only this computer that has the lack of 'automatic latching' problem.

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Answer 6

Linc Davis

Level 10

209,547 points

Feb 14, 2016 9:57 AM in response to Mike Gilchrist

According to many reports, the BT "HomeHub" router works better with late-model Macs if you disable the 2.4 GHz radio mode in its settings and use only the 5 GHz mode. Note, however, that very old Apple devices and some third-party devices may then not connect at all.

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Answer 7

Feb 14, 2016 10:31 AM in response to Linc Davis

Yes, I was thinking along those lines but disabling the 2.4ghz mode would knock out a few of our other pieces of kit so unfortunately it is not an option.

I really like the new Imac, the 32gb of ram and the 1TB of SSD really makes it fly for everyday tasks like program opening etc. as well as Photoshop and Movie editing....but this wifi 'quirk' is really irksome.

The need to select the router from the list of routers that it picks up (around ten from the dwellings around us) to access the network/internet is like a giant step backwards.

I will temporarily get hold of another router and see what occurs. BT have brought out a newer hub ......... it has been available for 'Home' fibre broadband for some time, but only recently for 'Business' fibre which is what we have installed.

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Answer 8

Linc Davis

Level 10

209,547 points

Feb 14, 2016 10:31 AM in response to Mike Gilchrist

You could connect a second wireless access point to the network in bridge mode and use it for the devices that don't support 5 GHz.

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Answer 9

Feb 14, 2016 10:55 AM in response to Linc Davis

Yes that is definitely a possibility but the fact that everything else is working great and that I have to invest in another router etc when a new computer 'should' be able to just hook up without faffing about seems not to be a very elegant solution.

I am dismayed that a new computer requires the purchase of another router in order to be able to do what it should do straight out of the box.

It was not a cheap purchase and I expect better from Apple.

I have been using their kit since 1984 and for quite a few years I ran my own Apple dealership alongside my IT support service for education and design houses (including Windows PCs as well).

During the bad years when Apple was struggling, I was a never say die advocate of the quality and ease of use of Apple kit and OS.

Up until fairly recently, when I retired from that side of the business, I have done many many upgrades etc for clients and only come across the odd problem which I could not iron out.

It was only recently that I took a leap of faith and progressed three of our older computers from Snow Leopard 10.6.8 to EL Capitan (as the new one was going to come with it already installed). All the older upgraded units are as good as gold........

This new iMac is annoying as it seems to be down to the fact that it has a problem in the 'handshaking' whereas the other kit does not.

Going by the many similar problems that are on Apple Support forums, I am not the only one suffering wifi problems with new kit or with EL Capitan....... Sometimes I now bite my tongue when a friend or associate have a 'pop' at Apple as obviously not 'everything' is perfect in the gear emenating from the garden of Cupertino.

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