... test :+12V, -12V, +5V, -5V, +3.3V,+5V Stand by (SB) 12V power Good ( PG )Voltage source : 20/24 pi Power Supply Tester The SD power supply tester ... voltage signal was not detected,or the detected voltage value over the normal,will issue a "DuDu" long buzzer,if ... source:20/24pin(ATX-connector) Voltage test:+12V,-12V,+5V,-5V,+3.3V,5V stand by (SB) 12V power good(PG) Connectors:floppy,HDD,CDROM,SATA ...