This PCI 4-digit PC motherboard diagnostic card will help you accurately diagnosis your computer’s non-working motherboard. No more listening for short and long beeps with this integrated LED character screen representing the possible cause of the problem. The diagnostic card is the perfect accessory for all computer technicians. The diagnostic card can pinpoint the exact reason when a computer does not complete POST perfectly. - 4-digit debug/diagnosis result code display - Multiple LEDs display communication status of the motherboard in realtime - Perfect for pinpointing the exact reason when a computer doesn't complete POST (bios boot) - English user's guide with diagnosis code lookup and description included