Dual Monitors analog + digital

Hi,
I've got 2 monitors, a 24" samsung on dvi & a 15" dell on vga. I have an nvidia gtx275 with dual dvi outputs, so I use a vga-dvi adapter for it to work on the dell.
All was working fine but the other day I opened by case up to plug a fan back in (didn't touch the graphics card) and then when I put it back together neither of the monitors work...
When I just have the dvi monitor plugged in it works, but as soon as I plug in the vga one then both of them go off (it won't even work in the bios with the vga plugged in) but then when I unplug the vga the dvi monitor will come back on.
I've updated the drivers, put the graphics card in a different pci-ex slot & made sure the vga monitor & cable work.
Thanks for any help you can provide :)

LOL! To add to what Pebbly said, connect the DVI to DVI in the top DVI connector and the DVI-VGA to VGA in the bottom connector on your GTX275.

Have tried both of those;
Now when I plug the vga monitor in, goto screen resolution, it correctly says Dell Monitor but when I click detect then the dvi fails.
Also tried another vga monitor, it didn't work even on it's own but DVI monitor works in both outputs.

You tried what Pebbly wrote already?

Yeah, I already had the case off

Didn't make a difference

Seeing as no analog monitors work on it, could it be an actual hardware failure? I've seen RAMDACs mentioned...?

Your card does support a VGA monitor with a DVI-VGA converter, I think the only way you can be sure if it is just your PC or actually your card would be to test it in another PC capable of handling your card. Does your motherboard have built in video as well?

It doesn't have onboard graphics, but I'll stick it in my old Dell & see if it works in there :)