PC DIAGNOSTIC 4-Digit CARD Motherboard POST Tester Be used to test motherboard problems 8 LEDs indication,easy to read LED Display on the Display,LED displays shows diagnosis result of motherboard. Especially helpful to pinpoint where is the problem when power on the computer and find no display or machine hangs up Diagnosis the motherboard signal which show the problem of CPU, Memory, video card, etc The POST code display is made up of a dual, dot matrix hexadecimal read-out that display's Power On Self Test (POST) status codes Support the power source working indicator -- +5V,+12V,+3.3V and 12V(When indicator LED is on to indicate its respective power is fine, otherwise to indicate its respective power is failure.)