Fangrui Product Details Features: Products Fully Support The Notebook/desktop Slot Interface, Is The Use Of Light-emitting Diodes And Light To Indicate The Data Line Address Lines And Other Signals Open And Short Circuit, Instead Of The Traditional Method Of Measuring With A Universal Meter Used To Repair Not Boot, Do Not Show, Do Not Read The Memory And Other Failure Of The Motherboard, Is To Repair The Computer Notebook/desktop Motherboard Essential Tools. Specifications: In The Tester Installed 3.3v (without Cr2032) Battery, Respectively, Into The Corresponding Notebook Motherboard Every Ddr4/5 Memory Slot, The Motherboard Without Power, The Test Light Is Full And Brightness Consistent, Indicating That The Signal Line Is Normal, If The Light Does Not Light Or Bright , Indicating That This Signal Has A Short Circuit Fault, With A Multimeter To Further Determine The Point Of Failure. Note: The Various Signals Of The Tester, Due To The Manufacturers Of The Motherboard Design And Chipset Of The Different Parts Of The Signal Ma