macbook pro not connecting to wifi... please help

positivenote

Hi guys,
my macbook pro (13 inch, early 2011) is giving me an error when I try and connect to my wifi at home:
"The Wi-Fi network "xxxxx" could not be joined.
Try moving closer to the wireless router. Alternatively, run Wireless Diagnositics to troubleshoot"

I am working right next to the modem?
There are no issues with other devices connecting to the network, and my macbook can connect through ethernet no problem.
I have updated from El Capitan to Sierra in the hope of fixing the issue but it hasnt worked. I have also tried to add new locations in system preferences>wifi settings... no joy.
I have also changed the wifi channel to no avail.
If anyone can help I would really appreciate it. Alternatively if there is anywhere that services macs in D.15 that may be able to help me with the problem it would be great
Thanks

positivenote

okay guys, this has gotten extremely strange...

as explained I cant get onto my wifi but now when I plug in the ethernet cable the wifi connects no problem, and then when i disconnect the cable and use the wifi the signal goes again after a couple of mins?
If any has any ideas id really appreciate it
Thanks

mikeecho

If you log in as a guest, do you experience the same issues ?

positivenote

mikeecho wrote: »

If you log in as a guest, do you experience the same issues ?

Okay, so I have just set up a guest account and the issue doesnt seem to be the same as the wifi has connected without an issue. This is a problem for me as I dont really want to have to rely on switching users to go on line or being restricted to using ethernet. Any way I can keep all my settings, book marks etc from my own user account? and how is this happening?
Thanks a million

Idleater

What applications or services have you running ? Anything like vpn or tunnelling?

positivenote

Idleater wrote: »

What applications or services have you running ? Anything like vpn or tunnelling?

no not running any apps like that at all..

mikeecho

positivenote wrote: »

Okay, so I have just set up a guest account and the issue doesnt seem to be the same as the wifi has connected without an issue. This is a problem for me as I dont really want to have to rely on switching users to go on line or being restricted to using ethernet. Any way I can keep all my settings, book marks etc from my own user account? and how is this happening?
Thanks a million

By using a guest account , and not experiancing the same prolem, you have proved that it it not a hardware issue.

I'm outta touch with the in and outs of macs, but i would suggest that you trash (dont actually trash, just put them in a folder on the desktop, so that you can always return them) the *.plist files that relate to wifi, network connections etc

positivenote

just an update on this chaps... now there is no wifi connection happening no matter what network i try. It says I should move closer to the router, even in college. Yet when i plug into ethernet cable I get connected and my wifi network preferences says I am conected to the wifi.
Any ideas would be appreciated again,
Thanks

mikeecho

You can try and delete all the saved wifi networks, then re-add them.
or trash the network prefs plist

or both


or you could try this

https://support.apple.com/en-ie/HT202222