[Meaven]

my new LCD monitor works fine using the VGA cables, but when i switch over to the DVI, it says no signal. any idea what could be causing this?

 

[PanamaGal]

Typically you go into the menu screen on the monitor and choose DVI as your input. Take a look at your on screen menu on the monitor and look around for it.

 

[TheMatt]

Make sure the DVI cable is DVI-D. Sometimes it won't work if it is a DVI-I cable.
http://www.playtool.com/pages/dvicompat/dvi.html