New MacBook Pro does not work with mini DVI-VGA adapter and Samsung 40" LCD

Discussion in 'MacBook Pro' started by afsimola, Oct 26, 2008.

  1. afsimola macrumors newbie

    Oct 26, 2008
    So I just got a brand new MBP and Apple's mini DVI-VGA adapter. My old MBP would hook up to the 1080p Samsung 40" LCD I have through Apple's standard DVI-VGA adapter perfectly fine. But now when I connect my new MBP the TV doesn't recognize the single. My MBP does read the TV and even adjusts when I plug the cable in, but nothing appears on the TV. I tried mirroring and changing resolutions, but nothing worked.

    Any suggestions??

  2. 7even macrumors 6502a

    Jan 11, 2008
    Wait, mini-displayport to DVI and DVI-VGA or is it mini-displayport to VGA? I am not sure the first would work because I don't think the DVI port on the mini-displayport-DVI adapter has the analog pins for VGA. If it's the latter, then I'm not sure.
  3. Chundles macrumors G4


    Jul 4, 2005
    That's mini DVI.

    You need a mini DisplayPort adapter, the new machines don't use mini DVI.

    If you want to plug it in with a DVI cable you'd need mini DisplayPort to DVI, if you want to plug it in with VGA you need mini DisplayPort to VGA.

    You can't do mini DisplayPort -> DVI -> DVI to VGA adapter -> VGA because the mini DisplayPort to DVI adapter only puts out the DVI signal, not a combined DVI/VGA signal and as such a DVI to VGA adapter won't work because there's no VGA signal to carry.
  4. afsimola thread starter macrumors newbie

    Oct 26, 2008
  5. NewMacbookPlz macrumors 68040


    Sep 28, 2008
    Same thing is happening with us MB guys.

    I think I read somewhere that DisplayPort is digital that VGA adapter Apple sells must have a DAC built in if that's the case.

    The dongle may not be able to bump the output power high enough for these TV's to recognize it. Mine worked fine on an LCD monitor, but NOTHING on the TV, didn't even see the computer (the computer saw the TV just fine). I went back and got the DisplayPort-->DVI dongle and then a DVI--->HDMI cable, and its perfect, 1080i output from the laptop.
  6. wahlaoeh macrumors newbie

    Nov 19, 2008
    ive just gotten my MB and its giving me the same problem. it is really frustrating the **** out of me. I have a Samsung LCD TV. just to confirm....what u did was. 1) and then 2) and it worked?
  7. robanga macrumors 68000


    Aug 25, 2007
  8. CaffeMacchiato macrumors member

    Nov 10, 2008
    The Mini DisplayPort (not mini dvi) to DVI out put is digital, not analogue. The audio information from the Mini DisplayPort is also lost.

    There are several types of DVI.

    * DVI-D (digital only)
    * DVI-A (analog only)
    * DVI-I (integrated, digital & analog)

    If you look at the DVI connector (female) of the Mini DisplayPort to DVI converter. You will see that it is a DVI-D. Therefore, the analogue signals required for VGA are not routed.
  9. Red-red macrumors 6502

    Jul 17, 2007
    Not the best of help but I went down the mini DP > DVI > HDMI route and it works flawlessly. Full 1080p, 1:1 match etc.

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