Flashing white/green pixels on external monitor

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Flashing white/green pixels on external monitor

Hello everyone, I just purchased a 15" MBP with the hi-res antiglare monitor. I upgraded from a black Macbook, which was connected to my 24" Samsung monitor with a Displayport to DVI adapter. When I bought the new MBP, I also bought a new miniDisplayport to DVI adapter. I just now hooked up my MBP with the new adapter to the Samsung monitor and there are/were two issues.

1) When I imported my photos off of my DSLR camera, I noticed green flickering pixels stuck on the images. These pixels moved and flashed with the image, so I know they weren't dead. When viewing those images on my regular 15" MBP monitor, those pixels were not there. They were only on the external monitor. I thought this may be an issue with my DSLR/image import, but then I noticed random purple/green pixel artifacts on an ad on Facebook as well.

2) I reset the NVRAM, flipped the DVI cord out and around, and reconnected it. Now, the green pixels do not seem to show up BUT there are now tons of tiny white pixels flashing across my entire screen. I disconnected/reconnected the display connector several times, and I was able to recreate #1 once. I haven't bena able to again.

I reconnected my old Macbook with the old adapter to the monitor and there were none of these issues.

What might be the problem? I can't capture the pixelation effect on screen capture.

I'm thinking its either:

An issue of Mountain Lion

My Macbook Pro's software

My Macbook Pro's hardware

The miniDisplayport adapter.

Thanks,

-Max

MacBook Pro, OS X Mountain Lion

Posted on Aug 8, 2012 6:19 PM

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Answer 1

newfoundmac Author

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Aug 8, 2012 7:39 PM in response to newfoundmac

Update: I connected my MBP to another monitor using the same cable and adapter, and the issue did not occur. This leads me to believe there is an issue with Mountain Lion and my monitor, the Minidisplayport adapter and my monitor, or the Thunderbolt port and my monitor.

The screen is a Samsung T240HD 24". If anyone with a mac running Mountain Lion or with a DVI to minidisplayport adapter could weign in on connections, I would greatly appreciate it.

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Answer 2

Jun 19, 2013 1:48 PM in response to newfoundmac

Having the exact same issue. I'm getting the problem on my LG Flatron E2742 external display, from a Thunderbolt to HDMI out from my 2012 MacBook Pro running Mountain Lion.

The issue began yesterday when I connected my MBP to a HDMI Projector. I noticed, via the projected image, the beginning of the dancing white/green pixels. What's really weird is that when I connected my MBP back to my standard LG External display, the dancing white pixels were still there!

MAYBE it's something that happeend to my thunderbolt to HDMI cable in the process? Haven't experimented with another cable to confirm this. BUT, something tells me it's actually software related, because when I first plugged in my external display this morning, it began flickering/staticing/spazzing out like CRAZY. After some poking around and forums, I eventually changed my display color profile and it went back to normal, EXCEPT for the dancing white/green pixels.

Any words of wisdom out there about this situation would be much appreciated.

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