Can't install monitor driver with VGA-VGA cable

[Smokey21]

Ok i installed a VGA-VGA belkin cable, to see if it sorts out my flickering screen.

Well it did, but once i connected the cable, i cannot install monitor drivers, and if there already installed, there not when the cable goes in???

It says it cannot detect any monitor? Using the DVI-VGA adapter, and the cable.

[Nick F]

sounds like something is wrong with the connections then mate, the wires should not change the driver in anyway. Try using a different DVI-VGA adapter.

[Smokey21]

I tryed a red one i got with the card, and one from my X800, same thing. I also tryed both DVI ports on the card?

Im totally stumped.

[Paul Adams]

My X800 Pro does ta similar thing - if I connect the VGA output to a monitor, then the monitor is correctly ID'd and the driver used.

If I connect a DVI-VGA converter, then hook that up to the HD15 input on the monitor then Windows does not detect the type of monitor connected and it becomes a standard default one.

My guess is that the DVI port uses the digital pins for ID'ing connected devices, so using a DVI-I to VGA converter means you lose this ability.

[Smokey21]

Dam, that sucks. I get what ya saying, but i have 2 DVI conectors on a 7800.

Guess ill just have to put up with a slighty fuzzy screen. It's obviously the DVi-VGA converter that causes the fuzzy text. If my 7800 had a VGA input, it would be ok, dam lol.

[herulach]

Do you really need vga drivers? I mean, as long as you can set the right res, what difference does it make?

[Smokey21]

Do you really need vga drivers? I mean, as long as you can set the right res, what difference does it make?

Well it wouldn't bother me really, but the screen flashes, when i click on system tray icons, and when i right click on files, and other stuff,the screen flashes black in a second, so i can't have that.

[SilentDeath]

The driver thing is not related to DVI connectors.

VGA cables have dedicated pins to detect the monitor. Without them windows wont know what monitor it is but you can manually tell windows what it is (supoprted resulotions, refresh rate etc..) by updating the driver. The driver is just a standard inf file I think. You can also edit the registry to change it. If DDC is enabled, you cant manually chose what resolutions or refreh rates windows think are supported. ATI cards let you disable DDC from the drivers, dunno iif nvidia has the option in its drivers.

The pins used on VGA for detection vary and some VGA cables dont have all connected: 4, 9 , 11, 12, 15. (9, 12 and 15 are the only ones needed on any monitor within the last 15 years!)
Its quite likely that a dvi-vga adaptor wont.

If you have a multimeter, check if pins 6 or 7 on the dvi side of the adaptor have a low resistanace to any of 9, 12, or 15.

VGA pinout + ddc info.
DVI-I pinout

However, the flickering can NOT be related to not having DDC pins. Is the flickering happening only when you do stuff? Sounds like a serious bug in the 7800x's bios, drivers, or a hardware fault.


Is your screen a CRT or TFT?
How was it connected before you got the new cable?
If they were both vga cables, do they both have all pins connected?

[Smokey21]

Screen is a CRT.

it was conected normally, using the small DVI-VGA adapter.

You say it can't be the adapters, but it is, with the cable used, the flickering goes.