Screen Flicker with External Monitor

Same exact problem...

What worked for me was switching the resolution to 1600x1200 and then back up to 1920x1200. This removed the flickering completly. I have a MBP13 Early 2011 with OSX Lion 10.7.3 hooked up to a Samsung 24" via TB->DVI

I just unpacked my new 15" MBP (2011) w/ Ci7 2,2 & ATI 6750 and out of the box I have exactly the same issue as with my 13" (2010) w/ C2D & GT320M. Upon connecting my Dell 2711 the screen starts to flicker (showing stripes from left to right for a brief moment over and over again). Any non-Mac machine that is connected to the display does not show this issue. Also switching to the ATI-Card permanently does not change anything. Only reducing the resolution from 1440p to 1080p or below resolves the Problem.

It's really about time that Apple resolves this very annoying Problem.

OK this is probably going to sound crazy but I have been experiencing the same problem for the past few months and presumed that my monitor was about to give up the ghost - intermittent flickering etc. I have a late 2011 17" macbook pro running a 5 month old Dell U3011 monitor via the displayport adaptor.

I just discovered that the issues are down to interference from my iPhone 4! If my phone is on my desk next to the monitor, then I get this periodic humming from my external speakers when the phone is relaying with the base station, and the monitor starts to flicker and go completely blank for several seconds. Pull the phone away from the desk and the problem completely goes away. I've tried it several times now and it never happens when the phone in near the desk.

Bizzare.

I can't guarantee this is what's happening to you, but it seems in my experience that most people who have Mac computers also have iPhones. You never know...

This is not the same Problem that I experience. When I start Windows on exactly the same machine ⚠ (late 2011, i7 MBP15) the problem does'nt appear! Everything runs smoothly and no flickering. Once I start Lion again, the flickering reappears. Therefore the problem occurs as a result of the OS and not of some hardware-defects. Could it be related to the graphics drivers?

I'm using a Late-2009 MacBook connected with a VGA Adaptor to a 22" Asus screen - in Clamshell mode

The screen has started going black and coming back on in the last couple of months

I seem to be able to force it to do it reliably by using Firefox (11 or 12) to display these pages:

http://www.squeakerclean.com/

(on this page, the screen will lose signal when the slider starts the transition to the next slide)

and

http://www.youtube.com/watch?v=u-dQIgfIFsI

I can use Firefox without the screen losing signal if I stay away from sites that have the Flash content...

If I turn off "Use hardware acceleration when available" in Firefox preferences, the problem is about 90% less

I can view those sites in Safari with no screen problems. (Using the same version of Flash Player)

So, for me at least, it looks like Firefox/Flash Player may be causing the problem....

Can anyone suggest where there might be a log file that could have info on what is happening?

I've got this too. 3 days after resetting my SMC, it's back. It appears to be triggered when I plug in my FW800 cable to my 27 inch iMac.

My MBP is a 2.3 GHz i7 with 16 GB RAM from summer 2011.

I'm plugging it in to my 2011 27 inch quad core i5 iMac with 16 GB of RAM using a mini displayport cable.

This also happens when connecting out to other monitors as well (Dell ala VGA).

Reset the SMC 3 days ago. Will do again after lunch. This is terribly annoying.

Reset SMC again (3rd time). Flicker is back today using my iMac and it's terrible.

Been having this problem with my 13" 2009 Macbook Pro and Gateway FPD2275W.

My solution was to find a resolution that allows for a refresh rate if 75 Hertz. Unfortunately, this means I can't use 1680 x 1050 resolution( the max for this monitor / macbook pro ), but at least I don't have flickering now.

Hello everybody,

I had some visual artifacts on external monitor (Acer 243hq) when connected to Display port of Macbook pro Early 2011 but solution was really easy for me. Firstly, I used Mini Display Port to DVI connector with ordinary DVI-D single link cable and noticed some digital noise on display at dark regions mainly. After that I found ordinary DVI-D dual link cable (some China cable for about $10-$15) and voila - digital noise disappeared !!!!!

I think You can buy any cable (not need to spend $100 for brand) for that. The main thing that connector should be of this kind (red square on picture):

http://i41.fastpic.ru/big/2012/0920/f2/1c935f118d087e34f75d1d5f230e2bf2.jpg

I've just found this thread as I am getting the same on an i7 2.2Ghz 10.7.3

I am using a Dell 1908Fpt with DVI from a Thunderbolt adaptor and occasionally the whole screen blinks and flickers constantly

It doesn't seem as if its the Monitor if that makes sense?

Then it can go for a while without doing anything - I assumed it must be the cable so I wiggle it around a little but it is locked in place. Any ideas on a solution?

What I've learned:

Move all electronic devices away from the cable. Cell phones, speakers, etc.

Also, I think there were notes to reset the Mac's power management unit. The SMC and PMU.

http://support.apple.com/kb/HT3964?viewlocale=en_US&locale=en_US

In any case, I simply ended up buying a Thunderbolt display after it came back. No problems since.

Hi all,

I'm glad to report, that I finally solved the screen-flickering issue that I reported some time ago (constant digital noise flickering with all MacBookPros on Dell 2711). Last week I searched Amazon for several miniDP-DP-converters/cables and after some consideration I simply ordered all of them ...

After some experimentation with different cables I discovered a working solution that produced no flickering at all. Therefore digital noise issues indeed do come from badly isolated cables/converters. For people experiencing the same issue I can recommend the miniDP-DP-cable from Manhattan (10ft, Barcode: 766623324830). On the other hand I cannot recommend the DeLock-cable (ASIN: B002U0YRFW) at all as I can reliably reproduce the flickering issue by just switching between the two cables.

The only thing is, that my formerly reported effect that only OSX produced flickering but not Windows 7 cannot be fully expained by cable isolation problems.

I really hope some of your setups might work again, too.

Cheers

Benny

My workaround is:

If the screen is flickering (usually when coming out of sleep), either unplug and re-plug the video cable or put computer back to sleep and re-wake it.

That usually solves the issue.

That also proves it's a software issue, nothing with bad cables.

This issue has been around for a few years now, why does Apple not solve this?