I use a custom built PC running Windows 7 (default) and Windows 8. I use Windows 7 primarily, and that's the OS I'm having the problem with, I haven't tried with Windows 8.
I've never had any problems at all with my monitors. I just restarted my PC today, and now one of them (my main monitor) isn't working. It's always worked before with no problems and I've changed nothing.
I use a Saphire 2GB OC Edition 6950 with the latest official drivers. It's all default settings, not overclocked.
I connect my secondary monitor (the one I'm using now, works fine) through the DVI port of the card through an adapter (DVI into card - converts to VGA DSUB to monitor as DSUB).
My primary monitor that's not working is an Acer one with VGA and DVI in. I use a cable which is male HDMI to male DVI, which has always worked before.
My card isn't overheating or anything, it's stable at 30C, and always is.
By "not working" I mean when the monitor is plugged in, the system recognizes it and acts like everything is normal, but on the monitor itself the screen turns on (so it detects a signal) but the screen stays black.
I suspect it's a driver problem, but not sure, so please help!
Extra info -
I checked the HDMI monitor with other HDMI sources using the same DVI to VGA cable, and it works fine with everything else. This tells me there's nothing wrong with the cable or monitor.
The card is still under warranty, shall I try and get it replaced? (I'd rather not do this, hassle)