Tracking down video problems

Discussion in 'Mac Pro' started by Phillie14586, Apr 26, 2011.

  1. Phillie14586 macrumors member

    Oct 14, 2010
    I have a mid 2010 MacPro that has had some video problems ever since I got it. I am trying to determine if it is a cable problem or some problem with the video card. I have a monitor connected via the DVI port and this has no problems. I have my TV connected via a minidisplayport with a MDP to HDMI adapter to HDMI cat 5 extender. This is what is giving me problems. Swapping out all this will cost over $100 so I would like to confirm that it is not a hardware issue with the computer if possible.

    I run the TV as a second monitor ans when I first set it up at the beginning of the year it would intermittently not detect the TV. I fiddled with things and removed some HTPC programs that were throwing a lot of things to the console logs. I finally got it working just fine for about 2 months. Now all of a sudden it will not always detect the TV. What I need to do to get it working again is to unplug the MDP plug and wait about 15-20 seconds then carefully plug it back in. It may take several times but eventually it will work. Just fiddling with the cables does nothing. There are times I get video but either no audio or audio with a lot of electronic distortion. The only way to fix this is to restart the computer. I am using XBMC as my HTPC software. What is new now is when I am watching a recording the video will go black and the audio will stop for 15-30 sec then the video comes back but no audio for another 15-20 seconds. I can rewind the recording to before it happened and watch with no problem through that section so i don't think it is a corrupted file.

    I have looked through console logs but I have no idea what I am looking for if there is a hardware issue. Any thoughts on how to determine if it is a video card issue before I start changing all the wires to the TV? One though I did have was to get a MDP to DVI adapter and connect my monitor to the other MDP port. If it is a MDP port problem then is should happen with both the monitor and the TV.
  2. Transporteur macrumors 68030

    Nov 30, 2008
    What happens if you connect the TV directly via miniDP - HDMI adapter without the CAT5 extender?

    Considering that a lot of people run that kind of setup without problems, my bet is that the extender is the source of your problems.
  3. Phillie14586 thread starter macrumors member

    Oct 14, 2010
    The problem has now become constant so I moved my computer next to the TV and connected with a MDP to HDMI adapter and tried two different HDMI cables. When I switch the TV to the input I have connected the computer to it says "Retrieving Data" then says "No Signal" When I choose an unused input all I get is "No Signal." I then moved the computer back to the desk and reconnected everything. Since I have the computer set up as an extended desktop between the TV and the desk monitor and I had just connected the computer to only the TV it thought the TV connection was the main monitor and the desk monitor was the secondary. So I turned the TV back on to see if it was getting a signal and it was not. So I unplugged the MDP and I got the desktop back on my monitor. But if I go to system preferences and select Monitors it only sees the desk monitor.

    My plan from here is to get another MDP-HDMI adapter and a MDP-DVI adapter. This way and I can swap the adapter going to the TV to see it it is the problem and I can connect my desk monitor to the computer using an MDP. Anyone have any other suggestions?

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