Mid 2011 iMac 21.5, MacOS High Sierra, WiFi/Ethernet failure?

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Level 1

4 points

Mid 2011 iMac 21.5, MacOS High Sierra, WiFi/Ethernet failure?

Good morning everyone!

I purchased the in title mentioned iMac off of my cousin. I am not exactly sure why he was going to throw it out and I can't find out exactly since he is unreachable while being overseas. His family told me it was something to do with the keyboard and mouse. I have since purchased a cheap keyboard and mouse from the good ol' Walmart, erased the disk and reinstalled MacOS High Sierra following instructions found here.

Almost immediately while using the Mac, the wifi would lose connection to my router. It would then stop showing all possible wireless connections in the area. When this occurred, I attempted to use an ethernet cord which too would not work and the Mac wouldn't even recognize a cord was plugged in.

The only temporary solution I have found is to restart the Mac. After restart the wifi and ethernet port work for a short time and then fail out again.

I have since erased the Mac and reinstalled the OS as a clean slate, erased all other wifi connections and re-established with my router, compared network preferences with my MacBook which is connected to the same router, and other possible solutions found on the web.

A lot of the solutions I have found are on the part of the router it self, but with the Mac not finding any other networks, including my iPhone's hotspot, and the ethernet port won't work either I feel as though it is an internal issue on the end of the Mac.

I have not found another issue quite like this one in the community and have searched the internet for the past day now to no success. Absolutely any help and advice would be greatly appreciated.

MacOS High Sierra Version 10.13.6

iMac (21.5-inch, Mid 2011)

Memory 8GB 1333 MHz DDR3

Graphics AMD Radeon HD 6750M 512 MB

Thank you in advance,

Mark

AATW

iMac 21.5", macOS 10.13

Posted on May 5, 2020 7:58 AM

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Answer 1

Best reply

rkaufmann87

Level 10

140,682 points

May 5, 2020 8:14 AM in response to MarkEdward89

Please do the following (yes, even if other devices connect okay in this order):

Verify the modem and router have up-to-date firmware. You will need to check their manuals for instructions
Restart Modem
Restart Router
Restart Mac
Retest

If the above fails please use https://support.apple.com/en-us/HT202663

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Answer 2

MartinR

Level 6

19,163 points

May 5, 2020 9:24 AM in response to MarkEdward89

Well, you may have discovered why your cousin wanted to get rid of the iMac. Just sayin'.

You could try resetting the NVRAM; doing so will not cause any problems and it may cure the network issue. To do this, when you start up your iMac, immediately hold down the Command (⌘), Option, P, and R keys. Keep holding them down until you hear a second startup chime. (Note, you should use a wired keyboard for this.)

It may or may not help, but it's worth a try.

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Answer 3

MarkEdward89 Author

Level 1

4 points

May 5, 2020 10:55 AM in response to MarkEdward89

Hey! Thank you for the quick responses. As of now, my Wifi has been operational for about 2 hours now consistently streaming youtube and doing some research.

I wish I knew which of everything I did worked for me, but as of now I'm rocking and rolling.

Thank you again!

Mark

AATW

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Answer 4

rkaufmann87

Level 10

140,682 points

May 5, 2020 10:59 AM in response to MarkEdward89

I'm not sure who you are speaking to, going forward when you reply to a message please click reply in that message otherwise it looks like you speaking to yourself. :-)

Glad it's working now though that is good news. If it re-occurs now you know what to do.

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Answer 5

MarkEdward89 Author

Level 1

4 points

May 5, 2020 2:43 PM in response to rkaufmann87

I have, and I am going through it again as I type this. I am currently using an Xfinity router, not sure if thats a problem for me. I am running the diagnostics again before going on the house PC and attempt to finagle with the router settings.

The wireless diagnostic summary reads:

Review WiFi Best Practices

LAN Connectivity Failure

Conflicting Country Codes

Under the LAN Failure, it states that I am connected to a wifi network that cannot communicate with my wireless router.

Any idea how I can fix that?

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Answer 6

rkaufmann87

Level 10

140,682 points

May 5, 2020 2:45 PM in response to MarkEdward89

If the router is working for other devices then it should be okay. As a previous poster said, you may have discovered why it was gotten rid of. Getting any computer used is a risky proposition. You can always get a USB - Ethernet adapter and try that if all else fails.

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Answer 7

rkaufmann87

Level 10

140,682 points

May 5, 2020 5:36 PM in response to MarkEdward89

Nope, iMacs are totally solid state which means the the wireless card is part of the main logic board. Obviously on a 2011 it's not available and even if you could find one definitely not worth fixing. You can see if you can find an external wi-fi card or you can connect it using Ethernet.

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Answer 8

MarkEdward89 Author

Level 1

4 points

May 5, 2020 5:41 PM in response to rkaufmann87

I will have to look into that. The problem with running the ethernet cable is when the wifi has shut down, I plugged in he ethernet cable and it did not recognize any cable was plugged in.

Thank you again for all the help through this, I appreciate you taking the time to assist me.

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Answer 9

rkaufmann87

Level 10

140,682 points

May 5, 2020 5:45 PM in response to MarkEdward89

Then it's really of no value whatsoever then and explains why you got it for free. Basically you got what you paid for. :-( If you really want a Mac and cannot afford a new one, then a) either save up or b) buy a used one from a reputable source such as www.macsales.com

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