With this LCD-equipped 12V ATX power supply tester, you'll learn more about your computers power supply than you ever thought you could. First, test every 3.3-, 5- and 12-volt rail to see if all the wires on the 20- or 24-pin connector are functioning properly. Then test all the power supply's peripheral connectors: the tester includes ports for Molex, SATA, P4, PCI-e and FDD power connectors. The built-in LCD shows PG (power good) signals and displays how much voltage is passing through each connector.