Use: computer mainboard maintenance tool [Specification]: Full-patch component production, LCD character display. Tip: USB is used for detecting the parallel port interface of notebook, and it only plays the role of power supply (because the parallel port interface has no 5V output). Instructions for use: Insert the parallel port card into the notebook parallel port (printing port), and then connect the USB cable (USB is the power supply! ). Turn on the notebook power supply, and according to the data display, you can judge the fault by referring to the fault code table of the diagnosis card. The characteristics of the four-position parallel port diagnostic card are as follows: Suitable for computers with POST code output to parallel port (). Flexible power supply mode, which can be connected to USB or computer host power supply; The code value of the "starting code" is a specific "0000" or "FFFF", which is clear at a glance. However, the code value of the "starting code" of the traditional two-digit code diagnosis card is uncertain and cannot be accurately distinguished by human eyes; You can refer to the internet. It can be fully compatible with high, medium and low mainboards from 286 to P IV, and the fault code is more accurate and reliable, without crashing; With the function of repeatedly checking the code, the code never flash by again. When you the switch once, it display a code and then pause; The diagnosis card only diagnoses the general direction of the problem, and it is not very accurate. The main function of the diagnostic card is to display the code of the motherboard BIOS self-test program. By referring to the display code and comparing the code description, the fault location can be found. It is not a universal tool! Color: Green & Black Material: PCB Package Contents: 1 * Computer Fault Test Card Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.