Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

10.8.2 External Display Issue

While the below issue was resolved 100% with 10.8.1 (the same problem occured back on 10.8), 10.8.2. seems to have reverted to the same critical bug. 😮


I use the HengeDock (a vertical docking station with the lid closed) with my Macbook Late 2008 Aluminium. When it is in the dock, the Macbook is starting up and shutting down (to and from sleep) when in the external display. The display is NOT broken (and neither is the cable) as it worked fine before upgrading TODAY and I CAN see the Apple logo during boot.


PLEASE help!


Thank you.


PS here is the link to a similar (if not the same) issue from 10.8:

https://discussions.apple.com/thread/4151965?start=15&tstart=0

MacBook (13-inch Aluminum Late 2008), OS X Mountain Lion (10.8.2)

Posted on Sep 20, 2012 5:36 AM

Reply
48 replies

Sep 20, 2012 10:13 AM in response to shmootz5

There is a solution, which helped me -


---

To execute in Terminal:

sudo nvram boot-args="iog=0x0"

To undo in Terminal:

sudo nvram -d boot-args

Once you type it into terminal I believe you need to enter your password. I then restart my machine. Now the TRICK is to either restart your machine with the lid already closed (hit restart then slam the lid!) OR turn the machine on for the first time (then quickly slam the lid!) once you are past the login screen you can open the lid.

ALSO: if the machine is asleep, and you simply forget and open the lid, it will wake up both displays. So just remember to wake the machine up with an external bluetooth mouse or keyboard.

Sep 20, 2012 3:26 PM in response to Jazzyalex

Thank you for the suggestion. I will certainly try it later today when I am with my monitor.


Would you mind letting me know what the terminal command does? (In terms of what it changes in the system to make this work, or if I have to use my computer differently at all). Is this something I always leave on (or should I turn it off after Apple does an update in the future)?


Thanks a lot! Much appreciated.

Sep 20, 2012 5:46 PM in response to shmootz5

I noticed simialr issue after moving to 10.8.2 on my hp external display. I was running kernel in 32-bit mode. After making sure it runs in 64-bit mode, all my external display issues are gone.


To set your machine to boot into 64 bit mode enter this command and reboot:

# sudo systemsetup -setkernelbootarchitecture x86_64


In case if you need to go back 32 bit mode:

//To set your machine to boot into 32 bit mode enter this command and reboot:

# sudo systemsetup -setkernelbootarchitecture i386


//To check which mode you’re currently in run this command in Terminal:

# sudo systemsetup -getkernelbootarchitecturesetting


I heard Mountain Lion does not support 32-bit mode, but it still allows to set to 32-bit mode, but i don't think it's really running in 32-bit mode.

Sep 21, 2012 5:18 AM in response to Jazzyalex

It seems you may have misunderstood my issue? The article says:

"You can still run a single external monitor if you close the lid of your laptop, but that restricts airflow and exposes your display to a lot of heat. Not good."


... However my issues is that I cannot use the external display with the lid CLOSED (I haven't tried with the lid open as that requires dismantling my HengeDock, which I will do tonight and let you know)


I hope that clears up my issue?

Sep 21, 2012 6:23 AM in response to shmootz5

Just to explain, I have tested my Macbook with the lid open (not in the HengeDock) and it DOES work with the external display. I assume your trick does work @Jazzyalex for the issue where the secondary display does not turn off; however my issue with the display not showing when the Macbook is closed still exists.


Thanks for your help!

Sep 24, 2012 8:23 AM in response to shmootz5

>sudo nvram boot-args="iog=0x0"


I had to this command so that my MBP lid can be opened while i work on external display. If the lid is closed i see my MBP is getting too hot and fans spin faster.


Until i movied to 10.8.2, to get my external display run in max resulution, what i have to do was, power on MBP, once i see login screen, close the MBP lid, and click on external key board or tracpad/mouse to get login screen appear on external display in full resolution. now i can open the MBP lid.


After moving to 10.8.2, if i follow above steps, my external display is not running in max resolution mode. what i found is after i power on MBP, just when you see spinning wheel, close the lid. after few mins you will see the login screen in max resolution on external display.

10.8.2 External Display Issue

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.