Introduction to computer hardware and software faults

First of all, I declare that my level is not high, so my mind is not low when I write this article. I just want to write my own experiences and hope to help all of you. Thank you.

Don't talk nonsense. Let's get started with the question below

To learn how to troubleshoot computer system faults, you must first understand the computer startup procedure.
The following is my summary After referring to other articles. There may be errors. For more information, see ~~~

To simplify the process, follow these steps:
1. The power self-check program starts running.
2. The Master Boot Record is loaded into the memory and the program starts to execute.
3. The Boot Sector of the active partition is loaded into the memory.
4. NTLDR is loaded from the boot sector and initialized
5. Change the real mode of the processor to 32-bit smooth memory mode.
6. NTLDR starts to run the appropriate small file system driver. The small file system driver is built inside NTLDR and can read FAT or NTFS.
7. Read the boot. ini file through NTLDR.
8. NTLDR mount the selected Operating System
* If NT/XP is selected, NTLDR runs Ntdetect.com
* For other operating systems, NTLDR loads and runs Bootsect. dos and then transmits control to it.
The windows NT process ends.

9.Ntdetect.com search for computer hardware and send the list to NTLDR to write the information into HKE Y_LOCAL_MACHINEHARDWARE.
10.then ntldrloads ntoskrnl.exe, Hal. dll, and system information.
11. Ntldr searches for a collection of system information and loads the device driver configuration so that the device starts to work at startup.
12.ntldrgrant the control permission to ntoskrnl.exe. At this time, the startup program ends and the loading phase begins.

Detailed steps:

First, when you press the power, the CPU points the command to the BIOS, the BIOS detects the memory, the video card, and then the speaker emits a clear "Drop,

Second, the system BIOS finds the video card BIOS, completes initialization, and displays the video card information on the screen.

Third, the system BIOS will display its boot screen, motherboard information, and so on.

4. The system BIOS checks the CPU type and operating frequency, detects the memory capacity of the machine, and displays the memory test value on the screen.

Fifth. the system BIOS begins to detect some standard hardware devices installed in the system, including hard disks, CD-ROM, soft areas, serial interfaces and parallel interfaces connected devices and plug-and-play equipment, now that all hardware has been detected and configured, the system BIOS will clear the screen again and display a system configuration list above the screen.

Sixth. then read the MBR (Master Boot Record) of the hard disk and check the hard disk partition table to determine the boot partition. Then, transfer the Operating System Boot Sector on the boot partition to the memory for execution, run the NTLDR (operating system loader) file.

7. Read the BOOT. ini file. Its function is to enable the system to display the selection menu during startup. The user selects the operating system to be started.

8. The system loads the NTDETECT. COM file. It detects machine hardware, such as parallel ports, display adapters, and so on, and returns the collected hardware list to NTLDR for later registration and saving in the registry.

9. The boot process starts to load the Windows2000/XP kernel NTOSKRNL. EXE. This file is located in the SYSTEM32 folder under the Windows2000/XP installation folder. Subsequently, the hardware abstraction layer (HAL) is loaded by the pilot process.

10. After the kernel is initialized, NTLDR transfers control to the Windows/XP kernel. The latter starts to load and initialize the device driver, and starts the WIN32 subsystem and Windows/XP services.

11th. Start the logon process. Start WINLOGON. EXE by the WIN32 subsystem, and start local security authority (LSASS. EXE) to display the logon dialog box. After a user logs on, WINDOWS2000/XP will continue to configure the network device and user environment. Finally, we entered the system and saw the desktop wallpaper.

All of the following fault phenomena are aimed at the startup process. No matter what happens, you can quickly take correct repair measures based on the above startup process.

My teacher said: After a problem occurs, first think about what you did before the problem occurs, and then try to restore the status before the problem occurs,

1. When you press the power switch of the chassis, but the chassis does not respond, the monitor has NO signal, and the display is NO SINGAL

Refer to the above steps: 1

Troubleshooting procedure: follow these steps to replace the power cord-chassis power supply-CPU-motherboard or motherboard BIOS
In this case, the hardware is damaged, and the software fault can be ruled out, and the possibility of the motherboard is greater than that of the CPU
I have met three exceptions: one is to accidentally turn off the POWER switch, the other is to loosen the POWER line on the motherboard, and the other is to loosen the POWER line on the motherboard.

2. When you press the power switch of the chassis, the power fan turns, the CPU fan turns, but you cannot hear the sound of the chassis horn "Drip", and the display shows no singal, words invisible

Refer to the above steps: 1

Troubleshooting steps: there are more problems. The CPU, video card, memory, and motherboard may be faulty, but the possibility of CPU and motherboard is lower. If the plugging of the video card and memory is invalid,
The replacement method is required. In this case, except for the BIOS chip damage, the hardware is damaged in other cases.

3. When you press the power switch of the chassis, the power fan turns, and the CPU fan turns, you also hear the sound of the chassis horn "Drip", but the display shows no singal, words invisible

Refer to the above steps: Second

Troubleshooting steps: the main problem is the video card and memory. If the plug-in is ineffective, it is basically damaged. You can only use replacement to find out the cause of the problem.
(Note: Some graphics cards can also pass the system BIOS detection after being damaged, but they will be black after the system BIOS detection is successful)

4. When you press the power switch of the chassis and the system completes the basic detection, you will be asked to Press F1 to enter the system,

Refer to the above steps: Step 1

Exclusion steps: Generally, there are English instructions. common ones are mouse and keyboard loss, CMOS power supply is not grouped, and FLOOP is not installed)

Troubleshooting steps: 1. Shut down the computer, re-unplug the keyboard and mouse, check whether the PIN is bent or broken, and re-tighten
2. Change the CMOS battery (or the leakage of the motherboard)
3. find the FLOOP device in the BIOS, disable it, and then find the floop seek option and change it to Diabled. In addition, in the startup sequence, remove the FLOOP startup option and change it to another one, save and restart.

A special example of using F1 to access the system:

A. WARNING: Immdiately back-up your data and replace your hard disk drive.
A forilure may be imminent

I don't know why, but it may be hard disk problems.

B. system bios shadown
Video bios shadown
NO Processor bios update found

This is generally caused by hardware replacement. Restoring the default BIOS value or refreshing the BIOS should solve this problem.
 
C. CMOS checksum error --- Defaults loaded
Darning! Cpu has been changed
Please enter cpu speed CMOS set up and remember to save before exit!

Generally, a similar error is reported after the CMOS discharge, or the CMOS jumper on the motherboard is reversed,
Follow these steps to restore the default value in the BIOS and check whether the jumper is in good condition.

5. After BIOS detection, the screen will be black for the moment and then it should be in the scroll bar status, but it will be black, reminding MBR to be damaged, or NTLDE (NTLDR is missing) loss and other information

Refer to the above steps: Step 6

Exclude step: MBR: If a Windows XP disc is available, after you start it with a Windows XP disc, select the second item "to use the Recovery Console to repair Windows XP installation, press the R key ". Press the R key to go to the Windows XP fault console. Enter Fixmbr or Fixboot, and press enter to restore the Partition Table errors in most cases. I found that using the fixmbr command can not only fix partition errors in Windows XP, but also be effective for Windows 98 and Windows 98/XP systems. The fixmbr command format is as follows: fixmbr [device_name (drive letter)].

NTLDR: This file can be extracted from the fault recovery console. This file is stored in the i386 directory of the installation disc. The extraction method is as follows:
Go to the system fault recovery console, go to drive C, enter "copy XI386NTLDR" (Note: Here X is the drive letter), and press Enter. If the system prompts whether to overwrite the drive letter, press "Y ", then enter the exit command to log out of the console and restart (only in the 2000 and XP systems)

Prevention measures: Pre-save MBR and OS loader files (one-key recovery): software and tutorial address html "> http://soft.yesky.com/SoftChannel/72347877992562688/20040816/1843045.shtml

6. after being guided through NTLDR, if it is a dual system or a multi-system, you will see the menu selection. If it is a single system, you will see that the scroll bar is running, but the problem occurs again, after the scroll bar, if the screen is black immediately (no single is displayed on the monitor) or blue screen, what should we do?

Refer to the above steps: Step 8

Exclusion steps: I can only talk about what I have experienced, but not all of them.

A. The most common is that the display resolution is adjusted to an abnormal frequency, for example, the frequency between 800*600 and 1024*768, or beyond the range.
B. the keyboard or mouse is in a half-broken and half-good state, or the pins are bent and broken (it will also appear when the user account and password are entered), usually a blue screen

7. finally, there is basically nothing else, and then you will wait to enter the user account and password to enter the system, and finally you will see the desktop, but then enter the input and press enter, the system is blue screen or black screen, and the security mode cannot be used.
There may be three reasons,
The first possibility is that the keyboard and mouse are not plugged in, the needle is broken, or the driver is not compatible with the motherboard. To solve this problem, you can replace the keyboard and mouse.
The second possibility is that the motherboard is faulty. I have met