How does the motherboard diagnostic card judge the motherboard problem?

First, plug the debugging card into the failed motherboard, but not the CPU, memory and expansion card, only the power supply of the motherboard. At this time, the main vibration light should be on, otherwise the motherboard will not vibrate; The reset signal lamp should be turned on for half a second and then turned off. If it is not turned on, the motherboard cannot be used without a reset signal. If it is always on, the motherboard will always be in a reset state and cannot be offline. Novices often plug the acceleration switch line into the reset pin as a reset line, which causes the reset lamp to light up, and the damage of the reset circuit can also lead to this fault. The frequency division signal lamp should be on, otherwise the frequency division part is faulty; +5V, -5V,+12V,-12V (new cards with +3V and -3V) four (six) power supply indicators should be bright enough, not bright enough or not bright enough, indicating that the switching power supply output is abnormal, or the motherboard is short-circuited or open-circuited; It is normal that the BIOS signal light does not light up, because there is no CPU, but if a good CPU is plugged in, the BIOS light should flash irregularly, otherwise it means that the CPU is broken or the jumper is incorrect or the motherboard is damaged. This function of DEBUG 2000 is quite effective. Voltage values such as -5V and-12V are rarely used in PC components. The -5V and-12V of the newly saved or long-term used PC power supply may have been damaged. Although they usually get along well, if something goes wrong, it will give you a headache. Now, this problem can be easily solved by debugging the indicator light on the card. After removing the above simple faults, plug in the related expansion cards (generally only constitute the smallest system), and according to the codes displayed after booting, you can directly find the faulty accessories, thus conveniently solving the hardware errors during installation, such as the contact errors of hardware such as memory, graphics card and CPU, and the functional errors of BIOS and CPU cache.