I've been searching for hours and nothing has worked. (HDTV as monitor)

Discussion in 'Mac Basics and Help' started by brmaki, Jan 2, 2010.

  1. brmaki macrumors regular

    brmaki

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    #1
    I'm going to be recording some music in the near future, and for the sake of convenience and not wanting to make everyone crowd around my Macbook, I decided to go out and buy what I thought I would need to allow my 2 year old Macbook to connect to my 42" Vizio. I purchased a mini display to DVI adapter and a DVI to VGA cable. The Vizio has an RGB/VGA input on the back, and I went with mini-DVI simply because I assume that would give me better quality if I end up buying a monitor at some point.

    Anyway, it seems that there are tons of posts all over the web describing my problem - plug everything in only to see a "no signal" message on the RGB input. My computer recognizes the display, will allow me to arrange it as if it worked etc. I've tried different resolutions, have the refresh rate at 60 Hz and have changed every setting around I could think of. I'm running Snow Leopard and the TV is about 2 years old as well. Any help is greatly appreciated as this has been a very frustrating experience. Thanks! -Brad
     
  2. DewGuy1999 macrumors 68040

    DewGuy1999

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    #2
    As I understand it, Apple's Mini DisplayPort to DVI adapter cable only outputs a digital signal and therefore should be properly called a Mini DisplayPort to DVI-D. Therefore, (unlike DVI-I, which carries both digital and analog) there isn't an analog signal for the DVI to VGA adapter to convert to VGA. I believe that a Mini DisplayPort to VGA adapter cable should work though.
     
  3. brmaki thread starter macrumors regular

    brmaki

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    #3
    Ok, got ya. I guess that makes sense, since there's really no digital/ analog converter anywhere in that setup. I'll head back to the store in the next couple days and exchange it for the VGA. Thanks!
     
  4. DewGuy1999 macrumors 68040

    DewGuy1999

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    #4
    I was thinking about this some more and I'm not real up-to-date on all the newer video stuff, but VGA is just so low res that it would seem like something better would also be available. Wouldn't a HDTV have an input better than VGA such as DVI or HDMI? If so, why not use the Mini DisplayPort to DVI adapter cable? Or get a Mini DisplayPort to HDMI adapter cable?
     
  5. Makosuke macrumors 603

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    #5
    If your TV has an HDMI input, you will probably get a noticeably better image by using the MiniDVI->DVI adapter you have with either a DVI-HDMI adapter or just a cable with DVI on one end and HDMI on the other (they're quite reasonably priced online, though you can get massively overcharged in a retail store if you're not careful).

    The Mac will recognize the HDMI output and send a proper signal to it; so long as your TV has a "dot-by-dot" mode (or something similar--depends on the brand), this will get you a perfect digital image at the TV's native resolution. With VGA, though it might be considered a "computer" input by the TV, it will generally be at least somewhat more blurry on account of the analog signal, even if the resolution is correct (which it often isn't--many TVs only accept a lower-res PC input and upscale it to the screen's native resolution).

    Incidentally, you said "mini display", which sounds like you're talking about a "miniDisplayPort" connector, as on the newest Macs, but if your MacBook is 2 years old I'm pretty sure it's just miniDVI. You wouldn't want to buy the wrong adapter.
     
  6. brmaki thread starter macrumors regular

    brmaki

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    #6
    My TV doesn't have DVI just VGA and HDMI. As far as the MiniDisplayPort goes, I just assumed that was what my computer has...the adapter I bought for it connects fine, and the mac recognizes the TV, the TV just isn't getting a signal.
     
  7. jMc macrumors 6502

    jMc

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    #7
    You'll definitely be better off attaching to an HDMI port. As miniDisplayPort doesn't output analog I don't think there's anyway to connect it to the VGA port on your TV without going through some kind of analog converter box. I have a miniDisplayPort to DVI cable which I connect to a DVI to HDMI cable and have no problem connecting to an HDMI port on my TV at 1080p. I believe you can get direct mDP to HDMI cables.

    DisplayPort, DVI and HDMI are all essentially the same thing just with different shaped connecters (and maybe the ability to carry audio or not).

    jx
     
  8. mkrishnan Moderator emeritus

    mkrishnan

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    #8
    FWIW, I think this is a basic misunderstanding of what VGA adapters do... VGA adapters can handle 1080p without problems... they really handle pretty much everything smaller than 30" computer displays (whose resolutions are much higher than TVs).

    The signal for VGA (and component) isn't digital, but it is high-resolution. There is sometimes a small difference between the image quality on the digital signal (DVI or HDMI) and the analog one (VGA or Component), but it's probably a lot smaller than you imagine, and frequently, it has more to do with the way the TV was designed than with VGA, since computer monitors work just fine at those resolutions using VGA, and have for many years.

    The biggest problem with these signals in TVs is usually getting the TV and the computer to agree on the parameters of the screen, so that the computer is displaying at native resolution on the TV.

    That being said, I previously connected the computer I have on my own HDTV via VGA, and I switched it out to a DVI->HDMI adapter and an HDMI connection at the TV fairly recently. This actually ended up slightly better for me. For whatever reason unique to my TV, it was much more friendly about setting up this computer (an EeeBox running WinXP) at native resolution on HDMI than on VGA, in spite of the fact that it worked very well via VGA on my iMac for a couple years.
     
  9. DewGuy1999 macrumors 68040

    DewGuy1999

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    #9
    Thanks for the education. I didn't know that VGA supported resolutions as high as used by HDTV. I'm still living in the dark ages with an old analog CRT TV that only has one input, coax. Someday, we'll get something newer, but for now it still works.
     
  10. akutad macrumors regular

    akutad

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    #10
  11. mkrishnan Moderator emeritus

    mkrishnan

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    #11
    A modern, digital television is beautiful. Even just watching 480p DVDs on it is beautiful. Although, I guess you have the benefit, via waiting, of getting an LCD backlight or even an OLED display, whereas I probably will use my current HDTV for another four or five years....
     
  12. brmaki thread starter macrumors regular

    brmaki

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    #12
    Ok, the output on my Macbook is indeed MiniDVI, so I picked up a DVI - HDMI cable and everything is working beautifully. I'll post a pic in the "Post Your Mac Setup..." in a few minutes. Thanks for all the help, I'm so glad that I finally got this working!!
     
  13. Makosuke macrumors 603

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    #13
    Just want to add that while VGA can indeed deal with relatively high resolutions (people forget that many CRT monitors could be set to ridiculous 1600x1200 resolutions), and often doesn't look all that bad, it does make a difference. I say this having gone from VGA to DVI on a few different dual-input monitors--the DVI input is noticeably crisper in terms of color bleed, and usually doesn't have the (admittedly subtle) "walking noise" of a VGA signal.

    There's also the fact that you can be pretty much guaranteed that your DVI signal will be mapped pixel-for-pixel to the LCD's native resolution, while VGA usually requires detection and can end up subtly offset. The situation is worse with TVs, which in my experience seem to do a remarkably bad job of mapping VGA inputs pixel-for-pixel.
     
  14. mkrishnan Moderator emeritus

    mkrishnan

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    #14
    Yeah. While my iMac worked, it required DisplayConfigX or SwitchResX to make it work. My EeeBox did needed edited DTDs, although both with VGA and HDMI. But in the end, it's on HDMI now and it's staying that way.

    I think I tried my DVD player once on HDMI as opposed to Component, and there, the sharpness was definitely noticably different, but actually, it looked better with Component because it was not so sharp. :eek:
     

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