# VGA works, DVI doesn't



## shokinezu (Oct 3, 2008)

I'm not actually sure if this is a video card problem or somewhere else, but it's affecting my video cards. I turned on my computer one morning and the monitor did not receive a signal from the video card. There have been no problems with my hardware before this whatsoever, and no warning signs. One morning it simply decided to stop working. This is my 4-month-old eVGA 9600GT card. After testing various monitors and monitor cables to ensure that those were not the problem, I swapped out the video card for my old 7600. This worked fine, but only if I used the VGA port on it. Worth noting is that my 9600 has only DVI ports. The 7600 has a DVI and a VGA port, but only the VGA port works. If I use the DVI port I get the same "no signal" message as on the 9600 card. Any clues as to what my problem is? I've already changed out the CMOS and flushed the BIOS, neither of those has helped. Any help would be much appreciated.


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## manic (Aug 2, 2005)

List all hardware specs, power supply wattage and brand also.


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## Wrench97 (May 10, 2008)

Is your monitor vga and your using a dvi to vga adapter? If so try a different adapter.


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## shokinezu (Oct 3, 2008)

Oh right, forgot specs.
m2n4-SLi Asus mobo
(currently) 7600GT card
AMD Athlon 64x2 3.1 GHz CPU
Thermaltake 550w PSU
Acer monitor
2 HDs, C drive is 120g Seagate, D is 700g seagate, no OS installed

And the problem isn't my monitor being VGA, my monitor supports both VGA and DVI, but only the VGA works. Since my 9600GT card ONLY has DVI ports, I can't get a signal. This isn't a setup problem, because i'd been using the 9600 for about 2 months before I got this problem.


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## Wrench97 (May 10, 2008)

Well the DVI is totally controlled by the video card so if you have checked the monitor and cable using a DVI out on another PC it will be a card problem It's hard to believe that 2 cards won't out put DVI but there is nothing on the MB that would make that occur, I'm assuming it also does not output on the Bios splash screen?


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## shokinezu (Oct 3, 2008)

That's correct, it will display absolutely nothing. As soon as I turn on the computer the monitor flashes, says "No Signal" and then hibernates. I don't have another card to test it, but for both the 9600 and the 7600 the DVI ports do not work, but the VGA port on the 7600 does. And up until 3 days ago, both cards were working fine with the DVI ports. Is it at all possible there was a driver update that caused this? I didn't install any drivers on purpose, but maybe it was a scheduled Windows update? I really don't know.


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## Wrench97 (May 10, 2008)

No a windows update wouldn't do it.
Do you have a dvi to vga adapter? Try using the adapter on the on the vga cable of the monitor to the 7600 card you have installed currently.


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## shokinezu (Oct 3, 2008)

I do have a DVI to VGA adapter, and using the VGA cable on my monitor to the DVI port on either of my video cards produces the "no signal received" message. It's definitely not a problem with any of the monitors or cables I have tried.


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## magnethead (Mar 18, 2006)

shokinezu said:


> I do have a DVI to VGA adapter, and using the VGA cable on my monitor to the DVI port on either of my video cards produces the "no signal received" message. It's definitely not a problem with any of the monitors or cables I have tried.


are you sure the DVI input on your monitor is working? Have you tested it on a known working machine?


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## shokinezu (Oct 3, 2008)

Hmm, no I haven't. I guess that will be the next thing I try. Would it be possible for that to go out overnight though? Because that seems to be what happened. Actually I know that's not the cause of the problem. I used the VGA adapter, so when using the VGA port on my monitor to the DVI port on either of the cards, I get no signal.


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## magnethead (Mar 18, 2006)

shokinezu said:


> Hmm, no I haven't. I guess that will be the next thing I try. Would it be possible for that to go out overnight though? Because that seems to be what happened. Actually I know that's not the cause of the problem. I used the VGA adapter, so when using the VGA port on my monitor to the DVI port on either of the cards, I get no signal.


but that's still the analog VGA signal. I'm thinking your digital processor in the monitor may have died from overheating or something.


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## shokinezu (Oct 3, 2008)

Alright, I'll give that a shot on my buddy's rig. Thanks for the idea, will post back tomorrow


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## shokinezu (Oct 3, 2008)

Yeah, the monitor works fine on a working computer. Also I've tried plugging a VGA-only monitor into either of my video cards to the DVI port (using an adapter) and it still gives the "no signal" message. Should i chalk this up to freakish coincidence and RMA my 9600 card?


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## Wrench97 (May 10, 2008)

Yes I would Rma it.


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## WhatNoNoNo (Feb 17, 2012)

Ah, 4 year old threads, timeless.

I'm having a similar issue; I have a 7600 GT video card with dual DVI ports and just the other day the DVI stopped working except as VGA. I bought a new DVI cable figuring that I'd been swapping the monitor between too many machines and damaged the cheap DVI cable I have -- but that wasn't it.

What I think it *might* be is power-related or some component failing; for the last few months I've been getting a high-pitched power-supply kind of noise but haven't bothered to start stripping out components to verify exactly where it's coming from.

So it might be that there isn't enough power or the wrong voltage or something like that that makes the video card fall back to VGA.

If it isn't that, I'm thinking that maybe a DVI pin inside the monitor may have been pushed out of place. In all other respects, the monitor appears to be working just fine and goes all the way to a slightly fuzzy 1600 x 1200 using the analog signal. Over the DVI cable the monitor shows only two basic lower-res resolutions topping out at 1024 x 768 (and that only shows after Windows loads, the BIOS shows nothing on DVI).

It's a weird one.


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## Wrench97 (May 10, 2008)

Try another video card.


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## WhatNoNoNo (Feb 17, 2012)

Got a new card today, mixed results. Now it displays on DVI during BIOS POST, but only has 2 resolutions available in Windows (1024x768 & 800x600). The VGA is still normal (but doesn't support the preferred resolution of 1680x1050). Also tried a quick re-install of Windows just to confirm it wasn't that.

The monitor is a viewsonic VX2025wm, looking it up on the web it turns out there's a lot of crazy problems with that DVI port not being recognized (and a viewsonic approved reset procedure of plugging in both the SVGA and DVI at the same time, powering everything up, shutting down, unplugging the monitor for 10 seconds or so, then booting up with only the DVI). There's other talk about the EDID being messed up.

Tried it all; it's probably the monitor in the end; it might be revivable if it really is EDID related, but I'm not holding out a lot of hope. It will probably get turned into a second SVGA-only monitor for me at some point.


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## Wrench97 (May 10, 2008)

Try setting the resolution you want in the advanced properties section of the resolution settings.


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