External Display Problem w/10.6.5

Hi, I have the same issue. It seems there is a problem with the 10.6.5. Apple has released on November 18, 2010 an update "MacBook Pro EFI Firmware Update 2.0" that could fix the problem.

I tried to apply it on my MBP, but it did not work. I got a message: "This software is not supported on your system."

Let me know if you have any news.

I'm having the exact same issue with an entire elementary school building full of brand spanking new (2010) white Macbooks that are using non-Apple (MonoPrice) Mini DisplayPort to VGA adapters. They no longer output video to the projectors unless you plug everything in and restart the MacBook.

Frustrating!

I hope that this issue is resolved in a forthcoming software update.

Same problem here with a brand new 10.6.5 mbp and 2 different original apple via adapters.

Not tried shutting down to force cable recognition - not really had to do that with any computers in the last 15 years or so. Not a very helpful approach to long - term tasks.

Something something quality control something.

I have a late 2009 13" MBP that used to behave very well with an external monitor via the Mini DisplayPort to VGA connector. Since 10.6.5 it does not recognise that the external monitor has been plugged in when running.

I was unsuccessful in getting the external monitor recognised on either restart or while running using the VGA connector.

However I was successful (last night) with a Mini DisplayPort to DVI connector. All connectors are Apple parts, the external monitor is a Dell 24" 1920 x 1200 and I have tested that the VGA input is functioning with other sources.

Yes. The problem is true. I cannot get my display to work. This includes my LCD TV, Projector at my school.

I use my installation CD to re-install 10.6.3. All data remains intact. It it is working now. Do not upgrade to 10.6.5.

I've experienced the same problems. I have been using my MBP with the same LCD projectors and same mini DVI to VGA adapter for more than a year without experiencing any issues. After the 10.6.5 update, my screen flashes after connecting my MBP to the LCD projectors but the the resolution does not change and no input is detected by the projectors. Even after manually adjusting the resolution the projectors detect no input.

I have recently found one projector that works with my updated MBP. After connecting the Optoma TS350 DLP Projection Display to my MBP the resolution changes to 800 x 600 (stretched) as expected followed by the input being detected and displayed normally.

Like some of you, I am also a teacher working regularly with LCD projectors in the classroom. This recent issue has been quite frustrating. My school was considering creating a Mac computer lab but after witnessing the recent problems interfacing their current technology with updated Macs they have now opted for a Linux lab instead.

I hope Apple resolves this problem quickly. Their incentives for educators and students are somewhat worthless if we can't use Macs in our schools.

Message was edited by: TenaciousB21

I'm also a teacher and I have the same problem. I'm having serious problems to teach my classes. And my word as macevangelist is with a great problem of credibility.

Anyone have found an temporary roundabout?

Apple please be hurry!

Late 09 MBP 13" here and same problem even after the firmware update.

I was in a class the other day and every MBP we tried with the update had the problem (3 machines) and 2 we tried could connect without a reboot. One of those was an older MacBook with the update and the other was an MBP 15" without it.

Just took delivery of an iMAC, my 2nd apple product.. my first being the iPhone 4 and I love it. I plugged in my external monitor (Samsung Syncmaster 225BW) and everything looked great. I then noticed 3 updates were pending.. iTunes Java and OS X 10.6.5. I downloaded and installed the 866MB of updates and rebooted. I lost my external monitor completely. Connecting and disconnecting the cable would add and remove it from displays but the monitor itself displays "no signal check your cable connection". I called AppleCare. She did not bother to inquire if my display was a monitor and wanted me to change settings on my Samsung TV. I told her my display and cable were fine as they worked when plugged into my Dell XPS but still insisted on asking me if I had another cable to try.. Ultimately she was helpful and had me pull out my 10.6.4 OS X CD and revert back. I read about the flickering and lines on external monitors but never came across a monitor receiving no signal so I thought I would post this.... First impressions are lasting impressions.

please all the people with this problem, send a bug-report to apple
https://bugreport.apple.com

they will reply with ann application you have to run to collect information of a vga-device that is not working anymore

I experienced the same problem but not immediately after upgrading to 10.6.5.
It happened 1 week later or so.
Apple please solve this problem I need to hold presentations and if the external projector does not run this is not possible.
Thanks,
cheers from Vienna
Christian

The 10.6.5 update is not the problem. My projector works just fine, exactly as it did before I applied the 10.6.5 update. It's a Mitsubishi XL5U, for anyone who wonders.

I'm having the exact same problem other posters have described, and it all started after I installed the 10.6.5 update. I can connect my 15" MB Pro to a DVI monitor at home with no problems, but when I disconnect it from my home monitor and connect it to the VGA projectors in two different classrooms at my university, I have to restart before the MB Pro will see the VGA projectors. This problem did not exist before the 10.6.5 update, and has repeatedly demonstrated the exact same behavior over and over again since the update.

Does anyone have a suggestion, other than rebooting each time?

I faced the same problem after upgrading to 10.6.5. But as I am still discovering my new MBP, configuring and installing various things along, it is difficult to be sure what was the exact reason of the problem...

Anyway, I solved it by downloading gfxCardStatus 1.8.1 and be sure that the NVIDIA graphics card was selected. Clearly, the external monitor is not working if Intel graphics card is selected.

Hope this helps.