I changed the DMA setting in BIOS from auto configuration to manual, saved it, and exited. Afterwards my monitor went black, and I can't even get BIOS to post when I manually power the computer on and off. It's a Phoenix award BIOS. I tried resetting the CMOS according to the motherboard manual (put jumper on pins 2 and 3 when computer is off and then switch back to pins 1 and 2, then power on the computer) All I get is a black screen. The monitor goes back into standby mode when I power it on and off. Thanks for your help.