Is it my DVI cable or Power Supply causing no signal to monitor

[mct]

I purchased a second hand motherboard from Ebay Gigabyte GA-EX58-UD4P
Connected it all up correctly. My monitor only has DVI and VGA ports, so went DVI from the graphics card MSI TwinFrozr3 GTX-660 2GB to DVI on the monitor.

The Motherboard powered up correctly but I was getting no signal on the Monitor. I did the usual checks, but still no signal

I decided to swap out the graphics card for an older style card that I have, this card has VGA, so this time I went VGA from the Graphics Card to VGA on the monitor, this time I did get a signal to the monitor.

I'm wondering if the DVI cable is the issue here, or my 700W power supply is not giving out enough power. 700W should be plenty for this?

I just purchased a bi-directional HDMI to DVI cable to see if this will fix the issue for the MSI TwinFrozr3 GTX-660 2GB that I want to use.

 

[mct]

No I didn't check the input on the monitor, so will give that one a try and get back to you.

I also tried another cable without any luck.

At least I know the motherboard is OK, and I don't think its the graphics card, as it worked fine on my other motherboard.

 

[mct]

I plugged in the DVI cable again and also messed around with the inputs on the Monitor like you suggested, and now the motherboard is working.
Thank you very much for your help.

I used to be handy building my own PCs many years ago, but it's only in the last year I have started buying newer hardware. New to me is stuff from 2012 onwards.
First rookie mistake I made was not having the correct power supply, as when I used my old ATX supply I didn't have a 6 pin connector for the Graphics Card