I am a Computer Technition. I installed a new power supply in a DELL everything is plugged in correctly and my PC is still not turning on I was thinking the board but the green LED on the board lights up when I plug in the new power supply. The old power supply tested fine on my multimeter and the new power supply tested fine. But still no sign of life thought maybe the switch but that looks fine. Computer is a DELL Dimension E510. ANY IDEAS!!!