Cause Analysis and Solution for failure to detect hard disk after computer reboot

World of Warcraft is so wonderful that I am deeply immersed in online games. However, after nearly two nights, I don't know whether it is a power supply or a mains supply problem at home, and the machine is shut down without warning. Even worse, after the power is restored and the computer is restarted, the hard disk is "missing. What's going on? I bought a GB Seagate hard drive for half a year. Shouldn't it be like this? Days !......

Check whether there are so many items! Restart again. In the self-check screen, press Del to enter the BIOS's "Standard CMOS Features" (see figure) to check the hard disk connected to the current system, but no matter how I set it, or the hard disk cannot be found.

BIOS Diagram

In a hurry, I immediately called laruence for help. Laruence said that in some cases (such as sudden power outages), BIOS hardware information may be lost. You can use the ClearCMOS jumper on the motherboard (the specific position and method of the Jumper vary with the motherboard, but there are detailed instructions in the motherboard manual) to reset the BIOS information to solve the problem. Unfortunately, this method fails after many tests. In desperation, only the most complicated replacement method is used for inspection. So disconnect the power supply, remove the hard disk, get a friend's house to check whether the problem exists on the hard disk. Not only can I identify my hard disk correctly, but also can access a Windows 98 system that has not been used for a long time (Editor's note: I use a Windows 98 + XP dual system, after you change the host, Windows XP may cause the system blue screen to crash due to the different Motherboard chipset, so it is much safer to enter Windows 98 at this time ), this indicates that my hard disk is correct. So what exactly is the problem? The computer can boot normally, and only the hard disk cannot be detected during self-check. What is the problem?

Take it home, then install the hard disk, boot again into the BIOS, and everything went back to normal, the hard disk was detected again. God! Why? Go online immediately and post on forums on major IT websites. Finally, I learned with the advice of some netizens that many of the current mainboards are equipped with motherboard protection circuits, especially the boards using Intel 865 and 875 series chipset generally adopt this protection design. This circuit is used to protect the motherboard, hard disk, memory, and other accessories when the computer experiences a sudden power failure that causes high current on the motherboard circuit. In the protected State, even if the host power is restored and restarted, its optical drive, hard drive, and other accessories will be in the protected and locked state, in this way, the hard drive, optical drive, and other data storage accessories cannot be correctly identified. To unlock the protection circuit, you only need to completely disconnect the power supply (unplug the power cord after shutdown, more insurance is to press the power button again) for a few seconds, then connect to the power source and start the system.