iMac 2011 - WiFi issue - Connected but no internet - High Sierra

[esbardu]

Hi,

my iMac 2011 (21,5 i5-2400s, HD 6750M) running High Sierra is behaving weirdly recently. After a couple of hours internet connection is lost even when WiFi shows that it is connected. The only workaround solution is to restart the computer.
Not sure how I can check if this is due to a faulty wireless card. Rest of iMacs/Macs and PCs at home work fine so I can not blame the router.

Anyone else has faced a similar problem with a 2011 iMac?

Thanks!

 

[Fishrrman]

Is the iMac anywhere near where the router is?
If so, have you tried using an ethernet connection (instead of wifi)?

Something else to try (might help, might not):
- power OFF the iMac
- power OFF the internet modem/router for about 30 seconds
- power ON the internet modem/router and give it a few minutes to get up and running
- now, power ON the iMac and see if it "finds" the router again.

Something else to try:
- open network (system preferences)
- on the left, click the entry for wifi
- now click the "-" sign to delete it
- when it's gone, RESTART the iMac
- go back to the network pane
- click the "+" sign and try to add the wifi network back.

Again, if there's any way you can run an ethernet cable and connect that way, it's the best solution.

 

[Juicy Box]

I have experienced a similar situation with two different Late 2012 iMacs. It would mostly connect to the network, but the internet nor any other network tasks would work.

Ethernet worked fine.

I never found a solution, and figured it was a faulty HW situation. Now, I am only using one of the two Late 2012 iMacs with the problem. I used an old AirPort Express and am using that to connect to my network as a wireless access point, and using the Ethernet port on the AE to provide internet to the iMac via Ethernet.

Not sure when I will do it, but I have plans to install a SSD in one of the Late 2012 iMacs with the messed up Wifi. I might try replacing the networking card and see if that fixes things.

 

[esbardu]

I have experienced a similar situation with two different Late 2012 iMacs. It would mostly connect to the network, but the internet nor any other network tasks would work.

Ethernet worked fine.

I never found a solution, and figured it was a faulty HW situation. Now, I am only using one of the two Late 2012 iMacs with the problem. I used an old AirPort Express and am using that to connect to my network as a wireless access point, and using the Ethernet port on the AE to provide internet to the iMac via Ethernet.

Not sure when I will do it, but I have plans to install a SSD in one of the Late 2012 iMacs with the messed up Wifi. I might try replacing the networking card and see if that fixes things.

I have even tried booting from an external drive with a fresh installation of Mac OS X.
Problem sometimes appear after 1 hour, sometimes after 2, no clear pattern.

I would buy an old Airport Express alternative rather than changing the internal card. Thanks for the idea.

 

[Fishrrman]

OP:

Gonna ask again:
Have you tried connecting using ethernet, to see if the problem goes away?

 

[esbardu]

OP:

Gonna ask again:
Have you tried connecting using ethernet, to see if the problem goes away?

I'm afraid that I can not use ethernet in the room where the iMac is located, this is an old house and my only ethernet is the router itself.
I would need to share connection from another Mac through ethernet, will try doing so.

 

[Nguyen Duc Hieu]

I'm afraid that I can not use ethernet in the room where the iMac is located, this is an old house and my only ethernet is the router itself.
I would need to share connection from another Mac through ethernet, will try doing so.

Fishrrman meant you can use the ethernet port to check.
It doesn't mean you have to wire a long ethernet cable from the router to your iMac, if it's physically impossible.
You can use a small wireless router with ethernet port to work as a wifi extender.
Set it to WISP mod, connect it wirelessly to the main wifi router.
Then you can just connect the ethernet cable between the extender and your iMac.

 

[esbardu]

Hi again,

I have moved the iMac to the second floor where I have a different WiFi router (Time Capsule 5th), problem is gone. It seems that there's an issue with the Internet provider's router, the one I use in the first floor. Rest of the devices work great in the first floor though.

I will try to find a workaround, don't want to mess with the provider's router.

Thanks to all for your tips and hints.