Thank You AnnEarl for your prompt response and excellent description. I performed all the above steps (minus trying to turn projector from on to "standby", mind you) - and yet it didn't work - was QUITE emberassing - Grand Round in a large hospital, lovely MacBook Air sitting there, no keynote presentation... First time in over 300 presentations from several poratble Macs in 10 years that I couldn't pull it off...
I HOPE SOMEONE FROM APPLE IS MONITORING THIS CONVERSATION AND FIX THIS BUG ASAP!!! NOT BEING ABLE TO GIVE A PRESENTATION FROM A 2012 MACBOOK AIR UNDER LION 10.8 IS ABSOLUTELY UNACCEPTABLE!
Exactly same problem. 2012 MBA 11 inch - [Have given > 300 presentations on a Mac) - had to give Grand Rounds. First presentation under 10.8.....NOTHING. LCD projector did not reckognize MBA. Why on earth is "detect display" now hidden (press option was the answer...) - nothing worked - restarting, "detect display", changing resolution, nothing.... PRETTY EMBERASSING - well I blamed Apple in fornt of a full house of physicians.
Went to genius bar @ Apple store - the friendly guy was unfortunately clueless and suggested to come back, if it happens again.
So now - like in the old days - I am carrying a jump drive with a powerpoint (exported from my keynote) to be prepared to give my presentations from a PC BECAUSE UNDER 10.8 I AM NOT ABLE TO GIVE A PRESENTATION FROM A 2012 MACBOOK AIR UNDER LION ANYMORE ...at least not reliably...
I am losing confidence in Apple.
My projector is recognized but two very large black margins appear on my computer screen. Doesn't matter what resolution is chosen. There is no option to stretch my screen so I can actually see it better.
Mountain Lion was released far too pre-maturely. Battery life and projector issues are what are plaguing me at present.
I don't have time for this.
So after several weeks of trying pretty much everything I can, including a visit to the Genius bar where the genius recommended buying Apple TV!!! I am now at this point.
Newer projectors particularly those with HD and that also do not have the option to change the resolution will not work with ML. Older projectors do occasionally work using the steps described in earlier posts, however this is very very hit and miss and is not reliable. As an example I managed to seamlessly connect to a projector a few days ago, however after completing exactly the same steps - nothing!!!
After the failures coupled with a seriously reduced battery life I bit the bullet and bought a basic laptop pc which has worked successfully worked every time, needless to say you can guess where my MBP is going.
I have to say that I feel very let down by Apple and their complete lack of proactive response; and indeed well done on a classic case of negative marketing in the best way. Everyone of the eight hundred central Asian participants that I have trained since my original post are now fully aware of just how poor Apple is!!
I've tried all the solutions suggested, but it's just can work only on some projectors, NOT the one in office .
It's so embarassing when I was about to present, and ppl questiond me and questioned my MBA 2012.
I just cannot find out any solution, any update software is released now? Absolutely not in the app store.
After yet another complete and embarassing failure to connect to projectors at a very important speaking engagement, I decided that was it for my MBA w/ Mountain Lion.
I contacted Apple Support. They guided me through wiping my disk and reinstalling Lion.
Today I have tested my the system on 6 different projectors/ plasma screens. 100% success. I will NOT upgrade to Mountain Lion for at least a year. There are too many bugs.
Same problem here.
Feel that i have to warn everyone who use projectors professionally. this problem seems to be totally random.
DONT USE A MAC WITH MOUNTAIN LION AS PRESENTER.
You cant be sure that you will get the projector working.
And to be honest, trying to make a presentation for 400ppl and only having a 13"screen is quite embaressing.
APPLE-Fix it or loose customers.
Luckily I dont use mine for work, but I have the same problem - No signal received by our projector.
I have to say, Im bitterly disappointed since paying the money to upgrade to Mountain Lion from Snow Leopard. I did so having heard that some of the bugs in iCal (failing to bring up some of the reminders on a too-regular basis) and mac mail (losing data) were fixed with the upgrade.
Instead I got a vastly inferior version of iCal, no synching to my phone which took 2 hours on the phone to apple care to fix, screensaver now unable to find images through the root directory, lags and the inability to connect to our projector.
Seriously, I thought I left windows to 'get everything under one roof' and simplicity, but I feel like Ive paid for a fancy box for a PC. Very, very angry and disappointed.
I hear your frustration. I do use my Mac with Mountain Lion as a presenter (currently on the East Coast US doing a three day seminar) and I have been lucky as I have yet to have ML fail me with a projector. I had some early frustration until I found the "detect displays" but since then it has been more stable for me (about a dozen different projectors) so far. In fact, a little better than Lion which itself was on par with my Dell with Windows 7.
My caveats are that a) most of the projectors I have connected to appear to be older (I almost always connect at 1024x768 60hz); b) I have only done the dozen or so; c) I have a Mid 2011 MacBook Air 11.
I am worried a bit that the next projector will be the one that I fail to connect to but it hasn't happened yet. I really get concerned when PowerPoint overrides what I set up and redoes the projector settings (often reseting to 800x600). I wonder if there is a conflict between my presentation software and what ML now wants to do.
I do know that if I unplug my "working" projection (to update something 'offline') and try to plug it back in, it mostly doen't work again and I have to start over from scratch.
Unfortunally ive had a realy bad day with two different presentations held by me and my colleague in different parts of the country and non of us could get the projector running.
Just spoke to the Apple support and they blamed the projector manufacturer, (how that could be possible as this was not a problem before ML)
my conclusion is that illhave to dump my new bought MBairs and buy PCs instead, at least until apple solves this..
Im so angry and frustrated that i really dont know what to do. I left Windows 5-6years ago as it was unreliable and slow to use.. but now.. guess there gona be a re-migration..
Dont think the 'Geniuses' at the store have any way of fixing the issue.. I would say that it needs a patch - badly..
My observations are as follows:
* 2012 Air - Lion before the software update - projector didnt work - banded display..
* 2012 Air - Lion - after the software update () - projector works, no issues..
* 2012 Air - Mountain Lion - needs restart to detect the projector - if I restart with the projector connected and switched on, it is able to detect the projector and work - same behaviour for both 10.8 and 10.8.1
* 2012 Air - Mountain Lion - with HDMI out instead of VGA cable - able to connect the display output to the TV *without* a restart being required..
[Luckily I got the Mac *just* before ML was released, and luckily I had a TimeMachine backup, so I've simply gone back to Lion.. ..waiting for Apple to release a fix..]
On a lighter note: A little while back, we were at the Apple store to watch the videos created by the kids at Apple Summer camp.. The machine they were planning to use was also running Mountain Lion.. Ironically, the staff there faced EXACTLY the same problem trying to get the output to the large projector/TV.. The person in charge tried a couple of things, and then decided to setup two new iMacs on the tables and asked the people to crowd around the iMacs.. I walked over to him and asked him to restart with the projector connected.. He said yes, he will try, and then continued with the iMacs!! The entire group waited for 20 minutes for the team at the store to connect these two iMacs and then crowded around the iMacs watching..
I have been an Apple user for over 15 years.. ..and to be frank, this is not the Apple I used to know.
I am having projector issues as well. My old MBP connected to projectors without fail. My new one is a different story. I have been through all the workarounds to no avail including what Apple support has recommended in the first round of conversations. I have tried different projectors as well. What I don't understand is that my friend running ML on new MBP 13" has no trouble finding the projector. My new MBP 15" won't recognize the same projectors that his does. Wierd and completely frustrating! I will be calling Apple tomorrow to see what else they can suggest. In the meantime, I spent a lot of money on a top-notch computer that won't perform the most basic of business tasks:-(!