Don’t turn off Wi-Fi in 10.9! (And how to recover a frozen Mac if you do)

Thanks to Ira for pointing this out. My old MBP has been stuck at 10.8.4 because of this problem. It sounds like I'd be safe to upgrade that machine to 10.9 by enabling WiFi in the manner described.

As an alternative to booting from the Install OS X Mavericks USB, it would be easier (assuming that you have another Firewire-equipped Mac) to simply boot the problematic MBP in Firewire Target Mode, and then make the edit that Ira describes on the target disk.

Hi Ira!

Just wanted to point out that single user mode can mount your hard drive in read/write if you issue the command:

mount –uw /

at the command prompt.

I had the same issue with my MBP late 2007 and the WiFi, but in my case I just reinstalled Mavericks and restored the Time Machine backup and everthing worked fine.

PS: I also suggest to use "nano" to edit the file, it's easier to use than "vi".

Do you have any more specifcs on how this occurs? I've got a couple of Macs running Mavericks that have had wi-fi turned on and off numerous times with no ill effects. It'd be nice to know the circumstances that you've experienced this.

D

Ira & AlfaMikeDelta,

Thanks for the detailed posts, they really helped me out. I've also got a late 2007 Macbok Pro 3,1, and got bit by this twice.

I first had this problem a few days after the Mavericks release, and at the time could not find any clues. It was baffling, because every kind of volume repair, safe boot, etc would not help, as you know. I also did not know what the triggering event was the first time.

The second time, I saw the pattern and was able to find the posts that you had made in between my two episodes.

Ira, here is a miniscule bit of additional information that may be of interest. It seems that it is possible to turn wifi off, if you have an ethernet cable connection.

Both times I got bit, this was the pattern:

1. Plug Mac directly into cable company router, via ethernet cable, and get an IP address from the router via DHCP (I was examining an ISP problem and so wanted to eliminate as much of my own LAN gear as possible)

2. Turn off wifi (the Macbook is still ok, and has IP 10.1.10.1 on the hard line)

3. Do something with the web browser (One time, my ISP was OK. The other time, I had no connectivity, but of course still had an IP address from the router)

4. Unplug ethernet cable--immediate freeze, failure to reboot

So, in my case, having a properly assigned IP address from DHCP kept me safe. As soon as both wired and wireless had no assigned IP, the trouble started. Not sure that is meaningful, but that's what I saw.

Thanks again fellas, this thread saved me hours of time and a lot of confusion.

If you have another Mac around, you can start the frozen Mac in Firewire target mode. Connect Firewire cable, boot holding the T key.

Then open /Library/Preferences/SystemConfiguration/preferences.plist in frozen Mac.

with Text Edit

and replace, as Ira wrote, false with true.

<key>PowerEnabled</key>

<false/>

Miguel

I tried disabling DHCP from both the client and server sides as best I could, but was unable to reproduce the freeze that occurrs when disabling Wi-Fi. Given that this issue is seen primarily on older MacBooks, I suspect it to be an Wi-Fi/Ethernet driver issue.

I bet you're right. Thanks for the update.

Hi everyone!

Just to add some more information, I have a late 2009 27in iMac AND I HAVE THIS ISSUE TOO!!! It freezes instantly when I turn the wi-fi off. Also, sometimes when I reboot after that, my usb Keyboard will not be detected until I reboot a second time. I don't know if this issue is related. I only became aware of it last week, and I was panicking because I thought my hard drive was starting to fail. But now I'm seeing I'm not the only one with this problem, so I'm weirdly happy.

If there's anything I can do to help, provide a log or something, just tell me what to do!

Francis

<Email Edited by Host>

What is this WiFi issue of which you speak? It sounds like you are thinking that some sort of system modification or misconfiguration is a problem with Mavericks. I suggest reviewing what changes you made and undoing them.