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I've recently decided that with my new nvidia GeForce 8400 GS graphics card that supports HDMI - I could do what I've always wanted to do, set up a multiple monitor system. I used an HDMI cable from/to my TV and then a DVI to my side monitor. Unfortunately nothing seemed to happen - it didn't recognise any monitor or TV on my computer, and my TV simply said "No Signal". I've tried a LOT of things to try and get this to work (as listed below) and am absolutely desperate to fix it.

Things I've tried/tested:

  • Tested the cable for another use (and it worked fine).
  • Tested the connection with a small very new TV on which the extended display worked
  • Tested the connection with a "regular" semi-modern TV on which it didn't work (and obviously it doesn't work on my intended display either).
  • Updated graphics drivers.
  • After a lot of trial and error got it finding my display and thinking it's outputting to it's fine, however I still get "No Signal" and can't see what it's trying to display.
  • Used Phoenix and monInfo (and regedit) to EDID patch the monitor when I got the situation above. This seemed to make no difference (still got "No Signal")
  • Tried other HDMI cables just incase.

Could anyone give and tips, advice or anything to try and help me out?

share|improve this question
What TV and what monitor are you trying to connect? I've setup two nVidia cards to drive 6-year-old Sony HDTVs, one with DVI and the other with HDMI. Both setups were recognized and the nVidia driver selected 1920x1080i resolution. Most consumer grade TVs accept only 1024x768 on their VGA port if they even have a VGA input. – sawdust Jul 16 '11 at 21:03
I've connected this TV via VGA before at my resolution (which is simply the TVs default resolution) however it just doesn't seem to work out with HDMI. It's a cheap "Acoustic Solutions" TV so it wouldn't surprise me if it doesn't have HDMI RGB support. – joesavage Jul 17 '11 at 6:24
up vote 2 down vote accepted

Many TVs do not support HDMI from a computer, and simply only support VGA-in.

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This. What's not advertised is that HDMI supports two color modes-- RGB and YUV. Most TVs use YUV, and computer graphics cards / monitors use RGB. They aren't compatible, and you'd need a signal converter to switch from one to the other. I want to say some monitors / graphics cards car capable of using / generating both color modes, but that's not always the case. – Darth Android Jul 16 '11 at 22:01
Ah - Well this is slightly annoying since I really want to have this dual setup. If I got a HDMI to VGA converter which got the HDMI signal from my computer and changed it to VGA for my TV to read - would this work? – joesavage Jul 16 '11 at 22:03
@Joesavage1 It should. – Darth Android Jul 16 '11 at 22:24

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