for starters, I apologize for my poor English. I will try to explain the better I can.
Mobo: Gigabyte GA-880GM-UD2H
Graphics: Integrated ATI Radeon HD 2450
Digital outputs (HDMI and DVI) work only with some (new?) displays. I have tried 5 displays and only work with 2 of them, the newest ones.
By VGA runs fine and if I plug a second display I can see in Windows that it recognizes perfectly both displays, but no image in the digital one. Restarting doesn't fit anything. Neither the preOS or BIOS screen is showed, absolutely nothing never.
It doesn't make sense for me. I don't know what else I can try.
I think you will find your problem is with DRM (Garbage, but forced to live with) Built into windows 7 and HDCP.
When connecting using DVI or HDMI the system will check/verify that the monitor is HDCP enable, if not it will "refuse" to send a signal to the monitor.
So if the Monitor must be HDCP enabled, old monitors are not. http://en.wikipedia.org/wiki/High-bandwidth_Digital_Con...
@RetiredChief But I can't see BIOS neither POST screens (before loading windows)... if it was hdcp I could see them and I would lost the signal later, no? (And considering you are right, because I think @aicom is)
Besides, I have more new graphic cards that certainly support HDCP and work flawlessly with these displays.
Any other idea? I can't find nothing on the Internet about this.