Unable to use projector on OS X Mountain Lion

Last week set up to present at a conference using same projector, adapter, and MacBook Pro (mid 2009) that had worked flawlessly in past. This time, since Mountain Lion, computer and projector would not see one and other. Very frustrating and embarrassing especially when I had to switch to a crappy old Dell laptop which connected without problems. Participants tried to assist and concluded "must be a Mac Problem". Don't know if revealing / using the detect displays would have worked. This unreliability & user unfriendliness is unacceptable. Apple should be using some of it's $137,000,000,000 cash on hand to ensure that the core functions of it's ecosystem "Just Work" - that is why I used to choose Apple. Without that they will decline into another replaceable gadget maker.

Sagacious wrote:

Last week set up to present at a conference using same projector, adapter, and MacBook Pro (mid 2009) that had worked flawlessly in past. This time, since Mountain Lion, computer and projector would not see one and other. Very frustrating and embarrassing especially when I had to switch to a crappy old Dell laptop which connected without problems. Participants tried to assist and concluded "must be a Mac Problem". Don't know if revealing / using the detect displays would have worked. This unreliability & user unfriendliness is unacceptable.

The problem is not the computer or the OS. I have no problems and I have the same computer as you. It is always a good idea to set up early and test everything out especially if giving a keynote or presentation. Do you have an extra VGA monitor lying around you can test the MacBook Pro (mid 2009) on?

P.S. The first post on this thread was 7/30/12. Still no fix. In their push to "innovate" have they lost sight of or ability to communicate with simple standard technology that just happens to be critical for use in the real work world? Will we all need to buy iProjectors?

Thanks, good to know. I agree about pre-testing early but was caught off guard as it always had worked. I may look for another projector to test and before next presentation I will see if I can get it to work with their projector but will have a backup for PC. I still think it's user unfriendly to have to know to use the option key to see detect displays.

the order in which you connect and disconnect the cable while the projector is on also plays a part. But to get use to it, test it out on an external monitor first.

I have an appointment with the Genius Bar on Wednesday. I used another mac Laptop running older ML OS. I had no problems.

interestingly enough I have no problem connecting to a TV with both VGA and HDMI cables. Whats up with Projectors???? Hopeing the Genius Bar can fix my problem.

Carlo TD: I'm sorry to disagree with you, but I believe this is a problem with Mountain Lion. You're right about testing first. But last week that made no difference. We connected everything, after figuring out the connection order (which we should not have to do), everything worked the morning of the presentation. Then when it was time to go live, we did exactly the same thing, and it couldn't find the projector. Apple decided that the "detect displays" button should be hidden, and require holding the option key.

We had to grab an older MacBook without Mountain Lion, which—as it should be—just plugged in and worked. This is a big deal for Apple because it's not just a technology problem users can get help for and fix. It's putting users through public embarrassment, and harms the brand. You here "it must be a Mac problem." That's not what Apple...or I need.

My problem exactly, and same computer and OSX version. Have you had any luck with Apple? Or did you get it fixed another way? Read about replacing the logic board but i think it may be a update bug. Please help

Same problem as Xtrunfe. I bought a DVI adapter, and it has worked flawlessly. However, most of the projectors at my university where I lecture do not have DVI ports; only VGA. I have to bring my PC to the rooms that have only VGA adaptors. Even Univ. of Chicago has addressed this problem: http://answers.uchicago.edu/page.php?id=26426

It may be a combination of OS and machine... I have a 2012 MBA 13" with OS X 10.8.2 and I have never been able to connect to ANY project properly. It always gives me a lower resolution with black stripes on the side. My friend has a brand new 2013 MBA, same OS version and it works perfectly. I am confused!!!!!

I've been following the discussions and had similar problems with my MBP 13 inch (mid 2012) 10.8.2

I bought an Epson Powerlite Presenter w/built in dvd for presentations - and had no luck connecting using Apple mini display port to vga adapter. Projector would never recognize the computer even after using all of the tricks mentioned above. I did remember one item from a post either here or on a similar thread on this issue. In any case the post mentioned a mini display port to vga (HD-15) active adapter. I bought one for about $15 online (Cirago). Just set it up remembering some of the hints above. Turned on the projector, turned on MBP, plugged in to the mini display port and, voila. Problem solved. After almost 4 months trying to find the answer. Finally.

Seems the active adapter adds another level of signal conversion. Hope this helps folks.

For me the issue was the adapter or dongle. I was using a third party brand. Once the guy at the Apple Store hooked up an Apple Brand the MBP detected the signal.

I have a macbook pro 13" retina display. I bought mini display port - VGA adapter and then I tried to commect my macbook to a Toshiba projector, but neither the projector recognuzed my mac, nir my mac ricognized devices. I went on display settings, monitor, but it was impossible to search deivices. There was only an unaccessible menu "airplay devices available"... I must project a keynote psentation, but if I don't solve this problem I cannot work. Please. Help me.

Apple has become a fat, slow, old lady. This discussion is going on for the past six months without a solution. Once you buy a machine you're stuck with it. It is a terribly embarassing situation, keeping your audience waiting because Apple didn't do its home work and continues not to do it. What can we do besides complaining? Sell your Apple shares, if you have not done it yet. Make the price go further down hill and maybe, just maybe, they will pay attention and start working.