New MacBook connected to external VGA display screen flash.

Yep, I still have the screen-flashes-randomly-after-wakup problem, even after the two recient macbook updates. Just to be sure we are all talking about the same thing.. here
is a video of my screen flashing and displaying horizontal lines. My aluminum macbook is plugged into a 20" mac cinema display.

http://www.youtube.com/watch?v=vK5psPOapXE


The only real way I have found to stop this screen-flashing, is to either
1. reboot
or
2. put to sleep and wake up
or
3. unplug and then replug the display into the macbook


Message was edited by: jwestveer

Message was edited by: jwestveer

same problem here:
mini display vga
samsung 2232bw
13-inch 2.4 aluminium

the screen go dark after 15-20 minutes

Same here. Not only flash, which occurs sometimes, but also get distorted with strange colors.
miniDisplay=>DVI
17" LCD
MacBook

Wondering if anyone else has had any luck by switching to the 9600M (those who have it, of course)...

Switching to the 9600M has solved the issue entirely for me.

willw9 wrote:
Switching to the 9600M has solved the issue entirely for me.

It seems that there are a variety of issues mentioned in this thread. Just to be clear, were you having the 2-3 second "blackouts," or one of the other issues?

I'm getting slightly hopeful...

i was having 1-2 second periodic blackouts

I can now also confirm that switching to the 9600M solved the 2 second blackout issue for me as well.

I just installed 10.5.6 and it also did not fix any of my issues.

10.5.6 doesn't fix the issue: still black flash during 1 or 2 seconds when it is connected to a external LCD 23''.

I can't trust this laptop to make a public presentation or conference.
I am going to return it.

The new osx release did NOT fix the macbook-screen-flashes-randomly problem here either.

MacBook Alu + LED Cinema Display 24

Mac OS X 10.5.6 doesn´t solve it.

Hi, I've been following this discussion with interest and I have been having similar problems. I have hesitated to contribute as I had nothing useful to add apart from "I'm having the same problem"! I have an Apple 20" cinema display connected to my new 13" 2.0GHz Aluminium Macbook using a Mini Displayport to DVI adapter. It was having some quite serious problems - a combination of all the other posts - flashing, black screen, snowy screen etc etc at random times. I had the same display connected to my previous white Macbook via a Mini DVI to DVI adapter and it worked perfectly for a couple of years. I use both screens at the same time for more space.
I agree that the two recent firmware updates did not solve the issue, but since installing 10.5.6 my problems have disappeared! It is interesting to see the most recent posts of users who have not found the update to cure the issues. Maybe I have not waited long enough and my problems will return. Watch this space.
I would however, encourage everyone who is having the problems to update their software and see if it helps them.
I originally thought the problems were the small size of the Mini Display Port and the larger adapter/cables pulling it slightly. But this isn't the case and in my opinion it would seem to be a problem with the new graphics chips. I hope this is of help to some of you out there.

Makes sense to me that this would not resolve the issue (10.5.6 Update) From what I have been reading this issue does also occur in bootcamp. This issue only occurs on the external displays and only with the 9400 card. this tells me it is a firmware issue on how the 9400 card talks to that new mini display port deally Apple has put on these new books. I am fairly confident if it is even fixable it will be a firmware update.

FWIW, I've never had issues using the Mini Displayport -> DVI adapter. I noticed intermittent blackouts only when I temporarily switched to the Mini Displayport -> VGA adapter while also moving to a larger screen with a resolution of 1900x1200. I believe the problem has to do with the Nvidia GPU struggling to support this large resolution with an Analog signal.

Once I switched to a Mini Displayport -> DVI adapter, even with the large resolution, the problem went away.

Some things to note: as the problem shows up in both Windows (Bootcamp) and Mac OS X, I believe it's most likely sourced at the Nvidia GPU. This means that Apple may have a tough time releasing a quick fix for it. They'd probably have to get something from Nvidia. Possibly a firmware update.

There is also a general rule that, to increase performance of a GPU, CPU, or any processing advice, you should keep it at normal operating temperatures; i.e. as cool as possible. Many chipsets have built-in mechanisms to decrease performance as it gets too hot.

Heat may especially become an issue if you connect your Macbook to an external monitor while keeping your Macbook lid closed. Closing the lid affects the heat dissipation and locks in heat that's emanating from the base of your LCD screen. You may notice, after keeping the lid closed and the machine on for a long time, that the GPU fan begins to whir very loudly. This is your Macbook trying to expel more heat.

Thus to help alleviate the issue, you may want to keep your Macbook lid open, even if you don't use its screen (lift the lid after waking it with an external keyboard). Also, keep the Macbook in a generally cool, well ventilated place.

But again, switching to a Mini Displayport -> DVI adapter has worked for me.


Good luck & Happy holidays!