... source : 20/24 pi Power Supply Tester The SD power supply tester is a robust voltage tester for PC power supply.ATX,BTX and ITX ... jack of the power test suite Power on the supply of power,will hear (DuDu" ring,if no flicker then the power supply output voltage is normal ... 5V stand by (SB) 12V power good(PG) Connectors:floppy,HDD,CDROM,SATA,4pin(P4),8pin(Dual-CPU),6pin(PCI-Express) power supply tester