5670 installation issues

[marshall_ryan]

Hello,
Looking for some help: just replacing a Radeon 5570 with a 5670. Hooked up the 5670, fired up my PC and no picture. Monitor can't see any DVI input. So tried HDMI, no love either. Figured fine, something wrong with the 5670, so took it out and put the 5570 back in.

No picture. Was all working fine with the 5570 this morning, but now I can't get any DVI out of it. Have tried 2 different DVI cables too, so it's not that.

Also, I don't have a VGA cable at the moment, so can't even check what is going on via the on-board gfx VGA out.

Any ideas what could have caused the 5570 to have stopped working? Thanks!

 

[marshall_ryan]

As a quick addendum, I don't get a 'beep' when I startup. (and as I can't get a monitor connected, I can't actually tell if the computer is booting normally and I just can't see it).

The hard drives kick in and the fans are all purring away. Just to make matters that little worse, my fancy wireless keyboard doesn't have a caps lock light, so I can't even check if that's responsive.

Starting to wonder if I could have somehow fried the motherboard, which would be odd and rather frustrating.