Q: MBA mid 2011 2.9 Firmware update just killed by Air

The EFI update writers need to put in a simple check in the pre-install and try and match the machine model available from sysctl as follows. It should prevent someone accidentally installing an EFI update for MBA 2011 on a MBA 2012. You can find your model in About This Mac. The system requirements section of this update is also erroneous and does not specify the correct old versions of the firmware to which this update can be applied.

sysctl -a hw.model

hw.model: MacBookPro11,3

Just great. I didn't even had the issue this is supposed to fix, but after the failed install I got it...

I installed update, and it didn't brick my machine, but I can't get Ethernet to work at all now. I have two USB Ethernet adapters and an Apple Thunderbolt Ethernet adapter and none of them work. They all work on my iMac, but in the network control on the MacBook Air they show as "Cable Unplugged."

Tried zapping the PRAM and doing a SMC reset, still won't work. At least I can still use WiFi.

You have bricked 'parts' of your machine. .

I'm a semi-lucky one.  It installed ok for me but now I'm having major WiFi problems, which I didn't have before.  I thought this update was to *fix* WiFi problems, not create them.  Now it never connects to my network when waking from sleep.  I have to manually point it to my network and tell it to connect every time I open the lid.

At least it didn't brick my MBA!

Yeah, I noticed this morning that mine no longer connects to Wifi after waking from sleep. So odd... it didn't update the firmware, but it introduced a new bug to my system. Apple, please FIX this shiznit!

Same here - installed update twice yesterday, first time MBA shut down but did not restart so i booted manually after about a minute. App Store indicated update installed but also available for install. Tried a second time, MBA shut down and eventually rebooted itself after about 5 minutes with same result: installed and still available for install. Having same problems having to connect manually to wifi.

Noticing the notification badge was still on my App Store icon, i clicked on it and discovered that the update available is no longer there and my two supposedly successful installation attempts yesterday are listed. Badge then disappeared after closing App Store. Can i assume the issue has been resolved and the updates were successful or is there still and issue and Apple is not informing us or what????

Like some above, I now have wifi issues ever since this update. Now I usually have to manually connect my wifi to the network each time I return from inactivity. Also I notice that skype now kicks me offline when I leave the laptop and does not recover when I return. I have to explicitly change my skype status to online. Also, my virtualbox running guest machine switches to paused and I have to explicitly resume it. Never had to do any of this before.

I too was having to manually connect to known WiFi networks on wake from sleep after 'unsuccessfully' installing this update.  I was going to try an SMC reset to see if that had any effect on this, but a simple full Shut Down and cold boot (not a reboot) appears to have resolved this, oddly.  Known WiFi networks are joined automatically on wake from sleep as expected now.  ¯\_(ツ)_/¯

Upon applying the EFI firmware 2.9 update, my MBA was bricked!

Fortunately, my original Apple Care covers me till end of this month (~whew)

Called in and Tech support shows me 2 tricks and I give it a swing

1. Hold down Shift + Power
2. Hold down command + R + power

I try those combo first time without power plugged in, but support said should plug in power and battery fully charge, so I give them a second try.

At first it didn't work I hold down those combo keys for about 5-10 secs

Screen still blank and not powering on

After I hung up the line, my MBA magically turn on (without even touching it)

Takes a while in the loading screen & am able to login.

Upon login, firmware is updated, try to shut down + restart couple of time and it seems alright.

Only catch is that now I need to hold down power button for ~ 5 sec in order to boot up the machine.

Anyways am happy my computer is back in action, really a magical Apple

The direct download link to the firmware seems to have been removed. I would highly recommend leaving your old firmware i place till an updated version is available.

Nowhere near as savvy as you guys but mine installed in much the same manner as others have mentioned; took around 5 minutes to restart.

However, my fan now runs a LOT more than it ever used to and my memory seems to fill up really quickly.

I use MemoryClean to flush it out and the fan slows down after the 3rd or 4th clean, usually when there is a gig or more free.

Luckily I don't seem to have wifi issues or weird startup happenings (yet)

Thanks natenate. Tried the full shutdown and cold boot, wifi issues seem to have been resolved.

Loner T, I will take your advice and wait for a new version of the update, thanks.

My 2011 MBA 13 went through the EFI update fine. No bricking. However, I find that the Wireless Connection is now impaired. Prior to this update, on wake from sleep, the MBA would connect to known access points in 1-3 seconds. Now, it just sits there. I need to manually choose the access point and connect.

The only change to my MBA has been this update yesterday, and the symptoms have been visible since then.

Is there any way to uninstall this update?