This network tester is a robust voltage tester for PC power supplies. Compliant with ATX, BTX, and ITX standards, it tests power supplies and displays voltage status on an LCD screen. Ideal for PC/PLC enthusiasts and for quick function checks in specialist shops. Simply connect the 24-pin power supply and P4, P6, or P8 connectors to the corresponding sockets on the tester. Power on, and you'll hear a "DuDu" beep; if there's no flickering, the power supply's output voltage is normal. If a specific voltage signal isn't detected or the voltage value exceeds the normal range, a long "DuDu" beep will sound. If the corresponding voltage value or PG also flashes, the power supply has failed. **Key Features:** Robust voltage tester for PC power supplies ATX, BTX, and ITX compatible Easy-to-read digital LCD display LCD screen displays voltage status Perfect for hobbyists and quick checks in repair shops **How to Use:** Connect the 24-pin and P4, P6, or P8 power supply connectors to the corresponding sockets on the tester. Turn on the power; a "DuDu" sound indicates normal output voltage if there's no flickering. A long "DuDu" beep indicates a voltage signal issue or a voltage value exceeding the standard; flashing voltage or PG indicates power supply failure. **Specifications:** Voltage Source: 20/24 pin (ATX connector) Voltage Test: +12V, -12V, +5V, -5V, +3.3V, 5V stand (SB) 12V output good (PG) Connectors: Floppy, HDD, CD-ROM, SATA, 4 pin (P4), 8 pin (Dual-CPU), 6 pin (PCI-Express)