Flashing green pixels when MBP is connected to external monitor

Discussion in 'Mac Basics and Help' started by Shotgun OS, Aug 8, 2012.

  1. Shotgun OS, Aug 8, 2012
    Last edited: Aug 8, 2012

    Shotgun OS macrumors 6502a

    Joined:
    Dec 18, 2006
    Location:
    Ohio
    #1
    Hey everyone, I just bought a new MBP 15". When I connected it to my external Samsung 24" monitor with a mini displayport adapter, some random images on the external monitor have flashing green pixels. These pixels travel with the image, so they aren't stuck on my Samsung monitor. Also, if I plug my old 2007 Macbook into the Samsung similarly (but witha displayport adapter), there are no green sporadic pixels. Any ideas?

    I reset NVRAM after a Google search but it didn't seem to help.

    Edit: After troubleshooting, it seems that the green pixel issue has changed into white pixels that sporadically pop across my entire screen. The issue may be with the DVI adapter or the Macbook Pro.
     
  2. DaLorD macrumors newbie

    Joined:
    Apr 21, 2011
    #2
    I got the same on my Samsung 55" LED.. after upgrading to ML..
     
  3. Shotgun OS thread starter macrumors 6502a

    Joined:
    Dec 18, 2006
    Location:
    Ohio
    #3
    My issue still persists, however, the pixels seem to mostly appear on heavy dark/black images or videos. The pixels are noticeable if I am close to my screen and watching Netflix, for example.

    I've come to terms with it for the most part, but it just seems to be some kind of incompatibility issue with ML.
     
  4. Alameda macrumors 6502a

    Alameda

    Joined:
    Jun 22, 2012
    #4
    Cable or DisplayPort adapter is the first place to look.
     
  5. Shotgun OS thread starter macrumors 6502a

    Joined:
    Dec 18, 2006
    Location:
    Ohio
    #5
    It's a monitor compatibility issue, at least on my part. I went and hooked my MBP up to another monitor with the same cable and adapter and had no issues.
     
  6. Alameda macrumors 6502a

    Alameda

    Joined:
    Jun 22, 2012
    #6
    Maybe. A monitor has a very high speed receiver, which needs to equalize the incoming signal. Some receiver chip equalize better than others. You might want to try a different dongle/cable.
     
  7. DaLorD macrumors newbie

    Joined:
    Apr 21, 2011
    #7
    Well I did not have this issue before upgrading to ML..
    On my 55" LED its easy to see the pixel-flash on dark backgroud and I'm sure they wasn't there using Lion..
     
  8. studiomatt01 macrumors newbie

    Joined:
    Mar 9, 2013
    #8
    basic solution found!!

    HI guys

    first time poster on here. I turned on my 2012 i7 MBP this morning which i have connected to an older 20" cinema screen via mini port to DVI to find green flashing pixels all over the place. Only bought it off ebay the other day and it's been fine until now.

    I tried a few things suggested on here and several other places, then went to pull the mini connector out of the MBP and suddenly noticed that as I pulled it out a couple of mm, the green pixels went away, as soon as I pushed it back in as far as it would go they came back. so I pulled it out a little bit again and flashing pixels gone!!

    left it like that for a while, then tried pushing it all the way back in again and the image is still fine.

    Very un-technical solution but it worked for me.

    best of luck guys

    Matt
     

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