Motherboard secondary DVI no signal

I just bought a motherboard with integrated graphic (intel) 3 outputs:

• 1 x VGA
• 1 x HDMI
• 1 x DVI

I've been able to use both VGA & HDMI but the DVI is not detected.

$ lspci

00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v2/3rd Gen Core processor Graphics Controller (rev 09)

$ xrandr
VGA1 connected primary 1280x1024+335+1080 (normal [...] y axis) 338mm x 270mm
   1280x1024      60.0*+   75.0
   [...]
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 connected 1920x1080+0+0 (normal [...] y axis) 160mm x 90mm
   1920x1080      60.0*+   50.0     59.9     30.0     25.0     24.0     30.0     24.0  
   [...]
DP1 disconnected (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

How can I make my DVI output to actually ouput something ?