I am building my first computer from scratch. I installed an ASRock 870 Extreme 3 motherboard into a CoolerMaster Centurion case, with 2X 4 gig Kingston Hyperion RAM modules and the AMD Phenom II 955 Black edition CPU. It is powered by AZZA Dynamo 850 W. All of these components installed nicely, and when I powered up, all the indicators turned on. However, when I held the power button for 10 seconds (and longer), the system would not power down. I had to manually cut the power from the power supply.
I pressed on. I then installed a PNY XLR8 graphics card with a GTS 450 gpu. When I connected my ASUS monitor and tried to get to CMOS and BIOS, the monitor would not read VGA or HDMI inputs. I tested the monitor with a different computer- the monitor works. I tested a different graphics card (that I know to work in a different computer) with the new computer- same problem. Can anybody tell where the problem is?