5 Replies Latest reply: May 7, 2012 3:27 PM by mazstar
mazstar Level 1 Level 1 (5 points)

I just bought a LG IPS 226v-PN monitor and am using a mini-dsiplayport to HDMI adapter to connect.

The monitor was automatically found and I can see and use it as a dual monitor but I am seen a snow like effect on the screen with pixel randomly activating (looks like snow).

The other problem is the screen keeps turning off and on.

I have switched it to both NTSC and PAL on the iMac. Not sure what I'm doing wrong?

iMac 21.5, Mac OS X (10.6.2)
  • Rudegar Level 7 Level 7 (23,620 points)

    have you tried the lg monitor on another source it be that it's defect or the adapter is

  • mazstar Level 1 Level 1 (5 points)

    Yes, I tried it on my Macbook Air and the same thing happened.


    I just tried it with selectin 720p for the external monitor and it is stable and dislaying fine except the resolution is completely out.


    I wonder if it will work better with a MDA to DVI cable - something in the LG manual says HDMI is for media sources not PC sources but I fail to see the difference - a signal is a signal isn't it?

  • Rudegar Level 7 Level 7 (23,620 points)

    sounds like the lcd panel is defect then

    what you describe is not normal behavior for any type of lcd monitor

  • iCare Level 4 Level 4 (1,765 points)

    The 'snow like effect' you describe could indicate you are experiencing timing/data corruption issues when sending a higher resolution data stream to the display. Could you post a picture showing the issue?


    What type of HDMI cable are you using, and how long is it? If it's longer than 10 feet do you have a shorter 6 foot cable that you can test with to determine whether cable length is a factor? Not all cables are created equal.


    What type of mini-DisplayPort to HDMI adapter are you using? Is it a good quality adapter?


    Here's more info on MiniDisplay Port that may be helpful.



  • mazstar Level 1 Level 1 (5 points)

    You gave me an idea and I tried another HDMI cable and it automatically just went to native 1080P and it seems fine.


    Good thing I only paid $4 for it! Saves me $30 on a DVI adaptor I was going to buy.


    I'm usually pretty logical with testing by exclusion but this time I assumed a cable is a cable.


    Thanks for the inspiration,