I had an HP Media Center m587 with two Dell flat panels connected to it (1702FP) with a NVidia FX5200 graphics card. For about six months it worked fine with two monitors (one connected to VGA and the other DVI). Then in September the DVI stopped working and therefore only one screen would work (ability to add second monitor was not there). After many calls to HP it was sent for repair and after 10 weeks they said it was a generic problem with my model and offered me a new one. Full system resets etc were all done but did not work.
Today I have installed the new HP Media Center m1190 (Windows Media Center 2005 with with ATI Radeon X600 Pro and it also has the same problem in that the DVI signal will not work (alone or in conjunction with a second monitor on the VGA socket).
I have tried:
Switching the monitors around and using a third flat panel
Trying different leads
Reinstalling the drivers for graphics card and monitor
Changing the BIOS
Using a DVI to VGA convertor (which works but doesn't explain why the DVI doesn't work)
Using the switch on the front of the panel to change the input (message comes up saying it's in sleep mode)
I have read through many forums and tried various solutions but it nothing seems to fix it. The option to add a second monitor is there but it doesn't do anything. It seems a lot of people are having this problem but none of the fixes other people have tried has worked for me.