Persistent WiFi Issues Even after Clean Reinstall

Been having wifi issues on a Mid-2011 MacBook Air. Basically once it is connected to a wifi network, it is not able to load any data from any web page. All 3 browsers I've tried (Safari, Firefox, Chrome) all had the same behaviour.

Had several troubleshooting attempts, including SMC reset, OS upgrades (now on Yosemite 10.10.3), deleting several plists and network locations, fiddling with DNS servers, all to no avail. Finally decided to have a completely clean re-install, wiping the HDD and re-installing from a thumb drive. First thing I try to do is connect to the wifi network and check the status of the problem. To my surprise it still occurs!!

I've kinda hit a brick wall here, so any pointers would be more than welcome. Weird thing is, once that MacBook is connected to the network, internet connectivity for all other devices seems to become very slow, almost dead.

polonoko said:

I've kinda hit a brick wall here, so any pointers would be more than welcome.

Click to expand...

You didn't mention if all these problems are occurring at one location...on one network (such as a home network). If this is true...I would take the computer out somewhere...and try connecting to a different network.

This will help determine if the problem is:

- internal hardware
- software/network settings

Or if it's external...such as a wireless router problem.

One thing I'm concerned about is. Unless you REALLY know what your doing...all the fiddling around (deleting things, changing settings) may complicate things.

- Nick

That's what I thought too, which is why I decided to go with the clean re-install, but even that didn't help.

Problem happens on several wifi networks, but interestingly enough, it works just fine with my phone's hotspot.....

Maybe Apple's article and utility could help track drown some of the problems.
How to use the Wireless Diagnostics Assistant:
https://support.apple.com/en-us/HT202663

polonoko said:

That's what I thought too, which is why I decided to go with the clean re-install, but even that didn't help.

Problem happens on several wifi networks, but interestingly enough, it works just fine with my phone's hotspot.....

Click to expand...

- If the problem is found on multiple networks.
- If a clean OS reinstall doesn't help.
- If things like an SMC Rset or PRAM Reset don't help.

Then pretty much the only thing left is an internal hardware issue. Fortunately if this is a 13" Mid-2011 MacBook Air...it does have a separate WiFi/bluetooth card:

https://www.ifixit.com/Guide/MacBook+Air+13-Inch+Mid+2011+AirPort-Bluetooth+Card+Replacement/6360

So if you feel like you've exhausted all other options...maybe a replacement WiFi/bluetooth card may help. Seems like they're fairly inexpensive as well (around $10 bucks or less on eBay).

- Nick

pigoo3 said:

- If the problem is found on multiple networks.
- If a clean OS reinstall doesn't help.
- If things like an SMC Rset or PRAM Reset don't help.

Then pretty much the only thing left is an internal hardware issue.

Click to expand...

But would it make sense that this behaviour would happen only on SOME networks? and it works perfectly fine if I connect through hotspot?

On the other hand, that is the only logical explanation if a clean install can't help the issue.

Thing is, if I was in the US I'd gladly order the replacement part and try to get it done, but I'm halfway across the world (Egypt).

polonoko said:

But would it make sense that this behaviour would happen only on SOME networks? and it works perfectly fine if I connect through hotspot?

Click to expand...

I guess it sounded like the hotspot was the only time the Wifi worked properly. And that ALL regular networks were a problem. Maybe I misread or misunderstood.

But if things do work normally on some networks & not others...this would be a VERY confusing issue. Since if only one network was the problem...then the problem could just be with that one network only...and not the computer.

polonoko said:

Thing is, if I was in the US I'd gladly order the replacement part and try to get it done, but I'm halfway across the world (Egypt).

Click to expand...

Yes...if you don't have replacement parts readily available...this does make things more difficult.

Just curious. If someone in Egypt does need replacement parts for an Apple computer...what are their options (especially someone who wants to do the replacement themselves)?

- Nick

pigoo3 said:

Just curious. If someone in Egypt does need replacement parts for an Apple computer...what are their options (especially someone who wants to do the replacement themselves)?

Click to expand...

Most common option is to look for someone who is traveling and ask them to get the parts from abroad / order them to their residence.

Recently some services have started operating where you can ship to a US address and they would handle re-shipping to your home address, I'll probably look into one of those...

If anyone has the knowledge and is willing to assist in a deep-technical troubleshooting exercise, I'd be more than grateful.

what type of wireless router do you have some wireless routers won't allow n cards to communicate with g routers

polonoko said:

Most common option is to look for someone who is traveling and ask them to get the parts from abroad / order them to their residence.

Recently some services have started operating where you can ship to a US address and they would handle re-shipping to your home address, I'll probably look into one of those...

Click to expand...

Thanks for the info! Both ways sound like good options...but of course not very fast options.

Can we assume that this computer did operate perfectly fine previously on all networks (including the networks that it now has problems with)?

Can we assume that you purchased this computer new...or did you purchase it used. And if you purchased it used...did you purchase it recently?

- Nick

pigoo3 said:

Can we assume that this computer did operate perfectly fine previously on all networks (including the networks that it now has problems with)?

Can we assume that you purchased this computer new...or did you purchase it used. And if you purchased it used...did you purchase it recently?

- Nick

Click to expand...

I took it (for troubleshooting and fixing) from a friend of mine, who bought it brand new.

It used to work just fine on any network. One day the monitor gave up, so it spent around 2 months unused, after which it went for a screen repair at an Apple authorized service provider, and came back like this.

Initially the problem went unnoticed as there was a problem with his home internet connection so he was living off his phone's hotspot, but once his landline came back he discovered this issue.

I know the circumstances imply that it is a hardware issue, but I can't wrap my head around why it works on some networks.

pm-r said:

Maybe Apple's article and utility could help track drown some of the problems.
How to use the Wireless Diagnostics Assistant:
https://support.apple.com/en-us/HT202663

Click to expand...

I've run that utility and it's left a report on my desktop that I can't open! So where from there?

EDIT: Did manage to open it with Console (10.10) but it's all Greek to me so I'm still stuck.

oisin said:

I've run that utility and it's left a report on my desktop that I can't open! So where from there?

EDIT: Did manage to open it with Console (10.10) but it's all Greek to me so I'm still stuck.

Click to expand...

I'm not sure but Apple says Wireless Diagnostics can use this report for further analysis, however that works, I'm not sure. Maybe as a base to extend further testing…???

Anything to help in the "Help" area?? Probably not if it's like recent versions.

oisin, why did you run the report? What problem are you having with WiFi?

MacInWin said:

oisin, why did you run the report? What problem are you having with WiFi?

Click to expand...

For the past couple of days it's been dropping off intermittently, while my TV, phone, iPod and iPad are unaffected.

Got it!
Finally contacted Apple Adviser and he put me right by means of this posting by BT I have problems connecting 5GHz and dual band devices wirelessly to the BT Home Hub 4 or Hub 5 | Help | BT.com Help
It seems the problem was caused by a recent hub firmware update. I wonder if other routers might have a similar issue.