Coolmax P/S Tester CoolMax ATX Power Supply Tester General Features: Plugs into ATX connector LED light and hear a sound if power supply tests good Can be use to test the large 4-pin (HDD) Molex, floppy, and 12V (P4) power connectors to check it it Connectors: 20-pin power connector 4-pin peripheral Molex power connector 12 volt (P4) connector Floppy connector