Macbook Pro to TV via VGA & RGB

Discussion in 'MacBook Pro' started by navycook86, Jun 30, 2011.

  1. macrumors newbie

    Joined:
    Jun 30, 2011
    Location:
    Ventura,CA
    #1
    I am trying to hook up my Macbook Pro to my Mitsubishi HD1080 60" T.V. I just bought a MiniDVI to VGA adapter and a VGA to RGB cable. When I hook up everything to the component in on my TV i get a bunch of purple squiggly lines then it turns blue. I'm not sure what I'm doing wrong here. Please Help.
     
  2. macrumors 68020

    Prodo123

    Joined:
    Nov 18, 2010
    #2
    Your TV has HDMI. Get a DisplayPort to HDMI connector cable.
     
  3. thread starter macrumors newbie

    Joined:
    Jun 30, 2011
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    #3
    this TV doesn't have an HDMI. It came out before that technology. It is a projection screen.
     
  4. macrumors 68020

    Prodo123

    Joined:
    Nov 18, 2010
    #4
    Well, you're going from a digital signal to analog. You're gonna have problems no matter what.
    Best way would be to go from Mini DVI-to-component, but I don't know if you have that or not.
     
  5. thread starter macrumors newbie

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    #5
    That's what I will be doing, RGB. The problem I'm having here is that the picture doesn't want to show up on the TV. I'm not sure if it's because I don't have it on the correct resolution or what? I know that the TV is picking up a signal because I can see a faint desktop screen before it goes blue.
     
  6. macrumors 68020

    Prodo123

    Joined:
    Nov 18, 2010
    #6
    Again, you're using a DIGITAL interface (hence mini-DVI = mini-Digital Visual Interface). It sends binary data over multiple connections to be translated into a picture. On the other hand, VGA is ANALOG, sending video not in an organized code but in raw data, divided into color channels like red, green and blue.
    Converting digital binary code into raw data and vice versa perfectly is very hard to achieve. It almost always has a problem, because in DVI one pin on the plug contains data for ALL color channels, while VGA allocates one color channel (red, for example) channel per pin.
     
  7. thread starter macrumors newbie

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    #7
    that makes sense. I was going about it this way because a friend of mine who works for Universal Studios Hollywood as a Technical Engineer told me they have done it at his work.
     
  8. macrumors 65816

    nunes013

    Joined:
    May 24, 2010
    Location:
    Connecticut
    #8
    i tried the same thing a while ago before i actually knew what i was doing.

    digital to analog= bad idea. the picture will not show up well. what you need is this

    http://cgi.ebay.com/PC-VGA-TV-HDTV-...622?pt=LH_DefaultDomain_0&hash=item519036ecb6

    i bought this and it worked. but im warning you its very blurry and a waste of money. if your tv has no digital inputs its not going to look good.

    EDIT: Prodo123, i tried that and composite and nothing worked. i spent weeks trying to figure it out calling apple once. I ended up finding the converter box. its powered with AC so it and change the signal. it shows up but... if you turn your computer to the lowest resolution thats how it looks.
     
  9. thread starter macrumors newbie

    Joined:
    Jun 30, 2011
    Location:
    Ventura,CA
    #9
    yah, that looks like it might be a waste of money for what i'm working with here. Why can't Apple come up with an Airport Express that does video?!?
     
  10. macrumors 65816

    nunes013

    Joined:
    May 24, 2010
    Location:
    Connecticut
    #10
    if it was through an airport express it would still be blurry as it has to convert the signal still.

    when i tried to convert it was a 20" screen and yours is 60" so it will be even more blurry.
     
  11. macrumors newbie

    stickygreen

    Joined:
    Jul 1, 2011
    Location:
    vancouver
    #11
    Mini DVI > VGA works fine, MiniDVI is digital and Analoug ( http://en.wikipedia.org/wiki/Mini-DVI see pin 20,22,24,29, and 31)

    I think the problem is your assuming that VGA is an RGB signal (component) it is not. VGA is RGBHV, or commonly refereed to as 5 wire connection (cause there are 5 wires) if your TV takes in Component ( 3 RCA connectors, red, blue, green) then you have to get a different type of signal from your VGA output, and the mac will not convert the signal on the video card, like some PC used to to. You would need a device called a scan converter, these can be very expensive. unless you buy a used one, But be careful, don't get a crappy one from China, they will look like ****, get one from a good brand name such as TVone, Kramer, Extron, ScanDo. This is probably not the thing you wanted to hear, cause the cost will be more than the final outcome is worth, personally, I'd just get myself a new TV...
     
  12. macrumors newbie

    Joined:
    Nov 4, 2012
    #12
    Thanks !

    Stickygreen, thank you for this useful comment. I also tought there was no digital conversion problem as VGA IS analog. I have the same problem and my hypotesis was mainly that it had to do with the "protocol" for refreshing the screen, or the refresh frequency, or the resolution. The picture on the TV screen looks like what you get when you were using a frequency that was too high on the old computer tube screens, except it has a pink hue.

    I thought maybe there are some softwares out there that carries the proper conversion? What I mean is : some software that would adapt the frequency and the resolution of the digital output to something appropriate for older TV screens. Then the digital-analog converter would output the proper signal too.
     
  13. macrumors 6502

    Joined:
    Dec 20, 2011
    #13
    Everyone other than Sticky green is wrong. Mini-DP and Mini-DVI (at least on Mac's, who knows there may be a only digital version somewhere out there) is D+A (Digital and Analog). Just like MOST versions of DVI is actually DVI-I (again Digital + Analog).

    Mini-DP/DVI to VGA is available all over, and they work just fine. And there is no DAC built in them (back to Mini-Displayport carrying a Digital and Analog signal).

    OP to try and answer your question. When you say "RGB" are you referring to a component cable? This is how I understand what you are trying to to. Mini-DVI > Mini-DVI to VGA adapter > VGA to Component cable. Where your problem lies is that last cable.

    VGA/15-Pin sync is separate, even though there is 15 pins, only 10 of them are used, and only 5 carry a signal. RGBHV (H & V being horizontal and vertical sync), each one has a ground as well (hence the 10 pins).

    Component, even though being the same signal, carries sync over the green channel. So unless you have a way to tell either the Mac (I am not aware of any) or your TV to convert the sync, you will see a image but the colors will be skewed. You more than likely need a VGA to Component convertor that will take care of the Sync change.

    Another issue you may run into (very common among older TV's), is what resolutions will your TV accept over component?

    ----------

    Come on man, don't recommend someone buy something when you yourself really don't know what you are talking about.

    Analog to Digital is fine, as long as you have a good convertor. And your convertor is not a digital to analog convertor. It is a SCAN CONVERTOR. In other words it will take a computer signal (according to the one you linked, it is VGA, which is analog), and scan it down to a SD input (composite, and S-Video which are pretty much the same).

    That is why your image looked bad. It has nothing to do with Analog to digital or digital to analog.
     
  14. macrumors 65816

    nunes013

    Joined:
    May 24, 2010
    Location:
    Connecticut
    #14

    ok im not getting into an argument here. i used to have an old rca only input on my tv before i got my HDTV. i wanted to hook my computer up to it and couldnt do it. i called apple and talked to their upper level support and they told me exactly what i wrote. they said the mac only supports digital out and my tv was analog in and therefore i needed a converter. then i believe i looked up here and someone recommended that box.
     
  15. macrumors 6502

    Joined:
    Dec 20, 2011
    #15
    Sorry, man I came off pretty brash. I own a business that is always connecting different signals and outputting through different outputs it display devices (A/V Rental Company, yes some of my switchers/scalers/scan converters are 15k+, but the basic idea applies).

    I think you are getting confused about digital. Thinking that digital = HD and analog = SD/Composite.

    MBP's can output a digital and analog signal. What they can't do (and this applies to just about all laptops in the past 10 years) is do a SD Composite signal. Your TV with "RCA Inputs" we're probably yellow/red/white? The yellow connection being composite.

    What is the OP is trying to do is go from his MBP to a analog HD component signal. Much easier, and depending on the TV the results may be acceptable. I would guess not as it is a RPTV :)
     

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