I just built a home PC based on a Biostar mobo and Celeron D 351 processor. When I power up, there are no POST beeps, no power or HDD lights, and the drives are dead. I know there’s power because the CPU fan is working and the CPU gets warm. The drives are good (I took them from another system) and I’ve checked and double-checked the power supply, jumper settings, and all connections. Any ideas??