1. AGP, PCI-E tester is used to test open circuit and short circuit conditions on the data bus connecting the computer card chip CPU and the motherboard PCI interface to ground. 2. When repairing computer card issues such as no display, blurry display, or unstable display, this tester eliminates the need to use a multimeter to individually measure the PCI bus interface between the card and motherboard. It quickly detects open circuits and short circuits with high accuracy, making it a reliable tool for card repair. 3. When troubleshooting computer card problems like no display or screen blurriness, first inspect for visible burn marks, PCB damage, and check if voltage levels are normal. If initial checks are normal, use the tester to verify the integrity of the data lines connecting the CPU to the motherboard PCI interface. 4. Connect a 12V power supply to the tester, insert the faulty card into the appropriate slot, and press the switch located in the upper right. The corresponding indicators on the tester should light up steadily. If any indicator is off, flashing, or shows significant brightness variation, this may indicate an open or short circuit related to the main chip or CPU. Use a multimeter for further fault diagnosis. Color: black Material: PCB + metal + plastic Package Contents: 1 x AGP PCI-E diagnostic card (The color and style of the graphics card slot are random; no specific selection is available) Only the items listed above are included; other accessories are not included. Note: Lighting and display differences may cause slight variations in the color appearance of the item compared to the actual product. Measurement error allowance is +/- 1-3 cm.