Shulou(Shulou.com)06/02 Report--

A complete list of hard disk failures

The meaning of hard disk mode in 2.BIOS settings

3.Fdisk cannot read the hard disk partition

Resolution of abnormal failure after 4.Windows XP hangs to hard disk

5. Maintenance record of scrapped hard disk

6. Analysis of common hard disk bootstrap failure

7. Snatch valuable hard disk data from death

8. Can the low frame eliminate the bad path of the hard disk?

9. Complete strategy for data rescue of faulty hard disk

10. Error opening hard disk partition

11. Solve the problem of multiple hard disk drive letter confusion

twelve。 Solve the problem of bad track of hard disk

13. Analysis and troubleshooting of hard disk guided failure

14. An effective method to unlock the logic deadlock of hard disk

15. Analysis and troubleshooting of hard disk failure during boot

16. Using DM software to regenerate the hard disk

17. A hard disk failure that stunned the maintenance staff.

18. How to solve the pause of the hard drive at startup?

19. Talking about the Common failure and maintenance of IDE hard disk

20. Skillfully erase the bad sector of the hard disk with Ghost

21. Skillfully install XP on a large hard disk

twenty-two。 How to repair the Bad Road of hard disk

23. What kind of "bad hard drive" can be repaired?

24. Talk about the signs and repair skills of physical bad track on hard disk

25. An example of saving damaged hard disk

twenty-six。 Several ways to save the hard disk

twenty-seven。 My hard drive takes a nap.

twenty-eight。 Small jumper to solve hard disk capacity limit

twenty-nine。 The experience of a hard disk data recovery

thirty。 One minute will teach you to identify the rerepaired hard drive.

thirty-one。 Five possibilities of Mobile hard disk failure

thirty-two。 Security loophole of hard disk protection card and its solution

thirty-three。 The hard disk number is one-point pass.

thirty-four。 The confusion that the hard disk can not be partitioned

thirty-five。 Data rescue after the hard disk is completely damaged

thirty-six。 There is a hardware failure in the hard disk, do you dare to repair it like this?

thirty-seven。 Common error prompts and solutions of hard disk

thirty-eight。 Technical terminology of hard disk

thirty-nine。 Summary of common faults in various parts of hard disk

forty。 4 cases of hard disk failure Q & A

forty-one。 Repair of Zero track and Partition Table of hard disk

forty-two。 Basic knowledge of hard disk soft troubleshooting

forty-three。 Basic knowledge and examples of hard disk soft troubleshooting

forty-four。 Experience of hard disk data recovery

forty-five。 A complete strategy for hard disk maintenance

forty-six。 Jump out of the misunderstanding of hard disk

forty-seven。 Analysis and troubleshooting of hard disk guided failure

forty-eight。 Skillfully repair hard disk with movable hard disk cartridge

forty-nine。 An example of repairing hard disk with Jinshan poison bully

fifty。 "four tricks" of repairing hard disk failure with Software

fifty-one。 Install Linux on the second hard drive

fifty-two。 Errors and operations that cause devastating failures of hard drives

fifty-three。 Correct installation of dual hard drives / dual optical drives

fifty-four。 Unable to install Windows 98 due to an error on disk

fifty-five。 The motherboard can't identify the hard disk dust as the killer.

1. Failure, cause and treatment of hard disk not starting

(1) failure of black screen

Reason: the data cable connected to one end of the hard drive is plugged back (it is impossible to plug into one end of the motherboard)

Processing: reseat it (the red line of the data cable is adjacent to the red line of the power cord)

(2) failure to display "Primary master hard disk fail"

Reason: (1) at least one of the hard disk data cable and power cable is not plugged in.

(2) the jumper of the hard disk is set to the slave disk, but the parameters of the CMOS hard disk are not modified accordingly (still the master disk)

Deal with: (1) insert it firmly

(2) reset CMOS

(3) faults without prompting information

Reason: (1) some numerical settings of CMOS hard disk parameters are incorrect.

(2) error or loss of master boot record

(3) error in the first important data (bytes per fan) recorded by the master DOS boot record

(4) error in file allocation table

Processing: (1) reset CMOS

(2) restore with FDISK/MBR command

(3) repair it to 512 with DISKEDIT.

Specific steps: start the computer with a floppy disk and run in diskedit / w / m mode; press Alt+P

Change "face 0" to "face 1", confirm; press F7 to view it as a guide record, and change "every"

The value of the term "fan bytes" is changed to "512".

(4) call the second allocation table with DISKEDIT and repair it with NDD (see the end of the article for download URL)

Specific steps: start the computer with a floppy disk and run diskedit; in the tools drop-down menu

Select "use the second FAT table" in, exit diskedit; and run ndd, select

For the Diagnostic disk item, follow the prompts step by step until you are finished.

(IV) display "DISK BOOT FAILURE,INSERT SYSTEM DISK AND"

PRESS

Failure of "ENTER"

Reason: (1) the hard disk and the optical drive are connected to the same data cable, and the jumpers are all set as the master disk (or both are set as the slave disk).

(2) set the parameters of CMOS disk to NONE

(3) 55AAH error in the end flag of the main boot sector

Processing: (1) set the optical drive jumper to the slave disk (or the hard disk jumper to the master disk)

(2) reset CMOS

(3) repair with the "diagnostic disk" of NDD

(5) failure to display "Error Loading Operating System"

Reason: the active partition flag 80H in the hard disk partition table is changed to a value other than 00H (such as

Change it to FFH)

Processing: using DISKEDIT to fix 80H

Specific steps: start the computer with a floppy disk and run in diskedit / m / w mode; press Alt+P

Enter directly without any modification; press F2 to view it in hexadecimal mode and put the 000001B0

The penultimate hexadecimal value of the address line is changed to 80.

(VI) display "Not Found any [ative partition] in"

Failure of "HDD"

Reason: the active partition flag 80H in the hard disk allocation table has been changed to inactive partition flag 00H

Processing: using DISKEDIT to fix 80H

Specific steps: same as (5)

(7) display "Type the name of the command,Inter preter"

. "

Reason: (1) error of primary DOS partition flag 06H in hard disk partition table

(2) command.com is missing, corrupted or different from the other two startup file versions

Treatment: (1) using DISKEDIT to repair to 06H

Specific steps: start the computer with a floppy disk and run in diskedit / m / w mode; press Alt+P

Enter directly without any modification; press F2 to view it in hexadecimal mode and put the 000001C0

The third hexadecimal value of the address line is changed to 06

(2) overwrite with the intact copy of the command.com file on the floppy disk (note that the version should be the same)

(8) enter d: enter (e: enter, f: enter) under DOS and display "Invalid drive"

Specification "

(note: this phenomenon does not affect hard disk boot, for reference only)

Reason: (1) CMOS hard disk parameter LBA is set to LARGE

(2) inactive partition flag 00H error in hard disk partition table

(3) some data errors in the extended DOS partition boot fan

Processing: (1) reset CMOS

(2) restore it to 00H with DISKEDIT

Specific steps: start the computer with a floppy disk, run in diskedit / m / w mode, and press Alt+P

Enter directly without any modification; press F2 to view it in hexadecimal mode and change the 000001C0 to

The penultimate hexadecimal value of the address line is changed to 00.

(3) repair with DISKEDIT

Specific steps: the situation is complicated and needs to be analyzed specifically.

(IX) display "Invalid partition table"

Cause: data error in hard disk partition table

Handling: repairing with DISKEDIT

Specific steps: the situation is complicated and needs to be analyzed specifically.

(X) display "Disk Iram O error."

Cause: error in physical hard disk flag number in master DOS boot record

Processing: change it from DISKEDIT to 80H (the first physical hard disk tag number)

Specific steps: start the computer with a floppy disk, run in diskedit / m / w mode, and press Alt+P

Change the default value to: column 0 face 1 fan 1, confirm; press F2 to view in hexadecimal mode, change 00000020

The fifth hexadecimal value of the address line is changed to 80

(11) display "Missing operating system"

Reason: (1) three data errors in the initial positioning in the hard disk partition table

(2) main DOS boot sector end flag 55AAH error

Treatment: (1) repair 1 face, 0 cluster and 1 fan with DISKEDIT

Specific steps: start the computer with a floppy disk, run in diskedit / m / w mode, and press Alt+P

Enter directly without any modification; press F2 to view it in hexadecimal mode and change the 000001C0 to

The penultimate hexadecimal value of the address line is changed to 00

(2) use DISKEDIT to repair to 55AAH

Specific steps: start the computer with a floppy disk, run in diskedit / m / w mode, and press Alt+P

Change the default value to: column 0 face 1 fan 1, confirm; change the last two hexadecimal values to 55AA

(12) display "Invalid system disk"

Reason: io.sys file does not exist

Handling: overwrite with an intact io.sys copy on the floppy disk, or transfer it with the sys c: command (note that the version should be the same)

(13) display "Non-System disk or disk error"

Reason: same as (12)

Treatment: same as (12)

(14) display "Failure..."

Reason: io.sys has been altered

Treatment: same as (12)

The meaning of hard disk mode in 2.BIOS settings

The motherboard now supports three hard disk working modes: NORMAL, LBA and LARGE.

NORMAL normal mode is the earliest IDE mode. When accessing the hard disk in this mode, the BIOS and IDE controllers are not responsible for the parameters

How to change. The maximum number of cylinders supported in this mode is 1024, the maximum number of heads is 16, the maximum number of sectors is 63, and the number of bytes per sector is

five hundred and twelve. Therefore, the maximum hard disk capacity is 512 × 63 × 16 × 1024=528MB. In this mode, even if the actual physical capacity of the hard disk is larger, the hard disk space that can be accessed can only be 528MB.

LBA (Logical Block Addressing) logical block addressing mode. The hard disk space managed by this mode breaks through the 528KB.

The bottleneck can reach 8.4GB. In LBA mode, the parameters such as cylinder, head and sector set are not the physical parameters of the actual hard disk.

When accessing the hard disk, the IDE controller converts the logical address determined by the parameters such as cylinder, head, sector, etc., into the physical of the actual hard disk.

Address. In LBA mode, the maximum number of heads that can be set is 255. the remaining parameters are the same as in normal mode. From this, it can be calculated that it is accessible.

The capacity of the hard disk is 512x63x255x1024=8.4GB.

LARGE large hard disk mode. This mode can be used when the cylinder of the hard disk is more than 1024 and is not supported by LBA. LARGE mode mining

The method is to divide the number of cylinders by 2, multiply the number of heads by 2, and the resulting total capacity remains the same. For example, in NORMAL mode, the number of cylinders is

1220, the number of heads is 16, the number of cylinders in LARGE mode is 610, and the number of heads is 32. So in DOS's view, the number of cylinders is less than 1024, that is,

It can work properly. At present, basically only LBA has practical significance.

3.Fdisk cannot read the hard disk partition

Symptoms: enter the DOS, enter the Fdisk command, do not see the partition data, followed by the string "error riading fixed disk" and return to the DOS prompt.

Treatment: Fdisk can not read the hard disk partition caused by damage, you can follow the following methods to deal with:

(1) run Fdisk/mbr from DOS to repair the partition.

(2) use the DiskTools of Norton Utilities 2000 to repair the hardware.

(3) use Pqmagic (partition magician) to repair the partition. Pqmagic has a more powerful repair success than Fdisk. As long as you start it, it can automatically check and repair some corrupted partitions.

Resolution of abnormal failure after 4.Windows XP hangs to hard disk

In addition to the beauty and security of the interface, Windows XP is considerate and convenient for users in many small places. For example, its current state is stored to the hard disk, and then the boot does not need to be initialized by the hardware, and the data is read directly from the stored state. Generally, it can be started in about 15 seconds, and the startup speed is greatly improved. However, due to the compatibility of hardware and software, you may encounter some anomalies when using this feature of XP. Here is an analysis and a reference solution:

The pronunciation of the onboard sound card is abnormal.

Now many motherboards come with AC97 sound cards. If the onboard sound card in your machine is a soft sound card, you may find that the sound is abnormal when you start up quickly for the second time after hanging to the hard drive. I have seen this is the case with a soft sound card attached to an elite SIS735 motherboard-not only the abnormal pronunciation after the windowsXP is booted quickly, but also the sound card does not pronounce at all when the windows98 exits to the pure DOS state and then returns to the windows graphical interface with the EXIT command.

Reference solution: since this is a hardware problem, there is little chance of manual adjustment. You can try to replace the latest driver, but if not, you'll have to buy an external sound card or honestly restart your computer. It is worth noting that in XP, the sound card still has a small hoarse sound, which sounds like the problem of the speaker is not the problem of the sound card, but it is actually caused by the re-initialization of the hardware before it can be reused. This is the real reason why I wrote this abnormal situation, so that everyone would not waste time on the speakers or even "adjust" them indiscriminately and damage them.

Second, the display is abnormal (blurred screen or black screen)

Some machines may appear blurred screen and black screen after starting up quickly or waking up from the SLEEP state. There may be three reasons for this:

1, the display card driver is not perfect: this is the lightest fault, you can find a stable driver version to install

2, the influence of the power supply power on the display card: some inferior power supply is not enough, which will cause the insufficient power supply of the AGP display card, while the fast reboot of XP no longer initializes the hardware and depends on the ACPI function of the motherboard, so it may have some impact on the power supply.

Reference solution: one is to adjust the power options in BIOS and windows to avoid using fancy features as much as possible. Second, you can set up a shortcut to a text file, put it on the desktop and add the shortcut key defined by yourself. When you press the shortcut key to start the text on a black screen or a flower screen, the content of the text may be displayed in part of the screen. Use more mouse clicks to switch the screen several times, and the display card may return to normal display because it refreshes the content in the video memory. This is a way to cure the symptoms rather than the root causes, but it is very practical, hehe.

Third, the mouse cannot be moved after a fast boot

This kind of fault is not a crash, and the keyboard is responsive. In fact, after the awakening in the previous windows9X, it also appeared. There may be two situations:

1. Your mouse is not compatible with the motherboard or power supply.

2. Your mouse is a fake, so there is something wrong with windowsXP when using the corresponding built-in driver, resulting in some BUG.

Reference solution: first try to unplug the mouse, and then plug in, the use of windows plug and play to detect the mouse again, but this may damage the motherboard interface for a long time; replace other brands of the mouse, preferably the authentic mouse; or the mouse connection from the PS/2 interface and serial port switch to try, some PS/2 interface of the mouse is not quite adapted to the new features of XP. By the way, don't underestimate the counterfeit problem of the mouse, thinking that you can use it-when installing windowsXP and windows2000, the installation often fails because of the fake mouse.

IV. Activation problem

Windows XP has added an active setting to prevent piracy. Some people install a version that needs to be activated in 30 days. If your motherboard battery is powered off and the boot date is not normal, windows XP may prompt you to activate before you can use it after the "Welcome" for quick boot. Because some people are greedy for convenience, they may use the function of suspending to the hard disk without saving or transferring some important documents, and when prompted for activation, because the activation function locks the system, you can no longer enter the graphical interface to deal with unfinished documents and lose the results of your work. This is not a real failure of a fast boot, nor is it very common, but it's a reminder that if you don't want to activate the product, pay attention to your date-because fast boot is a reboot after all, and windowsXP will detect it.

5. Maintenance record of scrapped hard disk

There are generally two kinds of fault prompts for hard disk self-test by microcomputer: one is "HDD Not Detected (no hard disk detected)", and the other is "HDD Control Error (hard disk control error)". The specific repair steps are introduced now.

First wash hands with water, the purpose is to wash the hands of oil and sweat, while releasing the static electricity that may remain in the human body. It is best to wear a pair of medical gloves before operating. All of my 15 hard drives can hear the sound of disk rotation during the self-test. The disk can rotate normally, and it is estimated that the main motor and the control circuit board are fault-free. For the hard disk with "HDD Not Detected" error, first check whether the interface of the external data signal line of the hard disk is deformed and whether there is virtual soldering in the interface solder joint. After ruling out the above possibility, remove the rear cover of the hard drive to expose the circuit control board. Unscrew the retaining screw on the control board and separate the control board from the main body of the hard drive. At this point, you can see two rows of springs on the main body of the hard drive. One row serves as the power supply of the main motor, the other row of magnetic head mechanical arm drive coil power supply as the main body of the hard disk and the data transmission interface between the main body of the hard disk and the circuit control board. For hard drives without special packaging, dust can often be seen in the corresponding parts of the spring and the control circuit board. Clean with skimmed cotton dipped in anhydrous alcohol, correct the deformed part of the spring, and remove the oxide layer. After the above treatment, my 7 hard drives have returned to normal.

If the above processing is invalid, you have to open the hard disk body. Choose an environment with little dust and unscrew the front cover of the hard drive (some are glued). Remove the front cover of the hard drive so that the surface of the disk can be clearly seen. First of all, the digital multimeter is used to detect whether the drive coil of the magnetic head manipulator is open. The normal resistance of the coil is about 20 Ω. Secondly, it is detected whether the connection on the magnetic head is disconnected. There is a magnetic head on both sides of each disk, and each head has two wires connected to the integrated chip on the head robotic arm. The common type of the chip is H1710Q, which converts magnetic signals into electrical signals and then sends them to the circuit control board for processing. The magnetic head resistance should be between 23 Ω and 26 Ω. If the magnetic head resistance is large, it means that the magnetic head is damaged. The head connection is connected to the chip H1710Q, and the corresponding pin resistance of H1710Q should be about 1.7k Ω. If it is below 1.2k Ω, the chip has been broken down and can be replaced with the cable.

If the connection on the head is disconnected, it can be replaced by a high quality enamelled wire from ∮ 0.2mm. One end is pressed on the metal shrapnel of the magnetic head, and the other end is welded on the corresponding foot of H1710Q. Note that the enamelled wire is stuck in the corresponding slot of the manipulator and fixed with a little 502 glue to prevent friction with the enamelled wire when the hard drive rotates. After each part of the hard disk is restored, the hard disk is sealed with 702 silica gel to prevent dust from entering. Because the volume of the magnetic head is very small, it is not easy to clip the enamelled wire on it, and it is best to operate under a magnifying glass. In my waste hard drive, the connections on two tie heads are damaged. I used too much force in the enamelled wire, resulting in a magnetic head damage, so only one hard disk was repaired and returned to normal after power on.

For hard drives that prompt a "HDD Controller Error" error, the files on the master boot record (MBR) of the hard disk are mostly damaged for some reason. MBR is located on the 0 head / 0 cylinder / 1 sector and is generated by FDISK.EXE when it partitions the hard disk. If the MBR is damaged, the microcomputer will prompt HDD Controller Error, in fact, the file on the zero track is damaged. At this time, formatting cannot solve the problem and must be dealt with by special software. First, after starting on disk A with the system disk, run the Scandisk command to check disk C.

If the zero track is not damaged, you only need to use Norton8.0 software to repair the files on the track. The specific method is to find a computer with the same built-in hard disk as the hard disk to be repaired and equipped with Norton8.0 software, and connect the hard disk to the hard disk power cable, but the hard disk signal cable is not connected, and the jumper remains the same. 1) run the Disk Edit command after boot, click the CONFIGURATION item from the menu Tools, cancel the Read Only item, 2) select the Driver item from the drop-down menu O-biect, set the Hard Disk type to Physical Disk, and click the OK item to determine; 3) select the Partition Table item from the Ob-ject menu, unplug the signal cable connected to the intact hard disk, connect it to the hard disk to be repaired, and click the OK item to confirm. 4) Select Hard Disk1, click OK to OK, and then set Cylinder, Side and Sector to 0, 0 and 1 from the Write Ob-ject to Physical Sectors dialog box and click OK to OK. Select the Yes item when the Warning dialog box appears. Exit the Norton software to restore the master boot information of the hard drive. Restart, the hard disk returns to normal, and the files in the original hard disk will not be lost.

If there is no track damage to the hard disk, first follow the above steps to deal with the Nor-ton8.0 software, but in the third step, set Cylinder, Side, Sector to 1, 0, 1, click the OK item to determine. Select the Yes item when the Warning dialog box appears. Quit the Norton software, restart the computer, in the CMOS settings hard disk automatic detection column, you can see that the CYLS value has been reduced by 1. If the original CYLS is 2112, it becomes 2111. It shows that the original hard disk partition table starts from the 0 cylinder of C disk, and now starts from 1 cylinder. Save the CMOS settings and exit. The hard drive returns to normal after repartitioning and formatting. There are another 3 hard drives, which prompt "HDD Controller Er-ror" during self-test. The above methods are invalid and can only be scrapped. If you have a bad hard disk in your hands, you don't have to abandon it first, but you can first repair it according to the above methods. I believe there will be unexpected gains.

6. Analysis of common hard disk bootstrap failure

General hard disk bootstrap failure, if not the main boot sector or DOS boot sector is destroyed (such as infected by a virus), then other symptoms are basically caused by some hardware failures related to the hard disk. The software can use antivirus software to check and kill the boot sector virus, or use NORTON, DEBUG and other repair (more troublesome), while the hardware can be analyzed according to the information indicated after the power-on self-test.

1. Post completes with the following error message: HDD controller failure Press F1 to Resume

When the above information appears, we should focus on checking whether the interface of the power cord and data cable related to the hard disk is loose, bad contact, signal cable connection, etc., and then check whether the jumper of the hard disk is set incorrectly.

two。 The following message is displayed after post: FDD contreller fanilure HDD contreller failure Press any key to Resume

The above information is usually connected to the soft and hard disk parts of the bad contact or damage, which is more troublesome, light can also be repaired, serious may have to be replaced.

3. Boot displays the following message: Drive not ready error Insert Boot Diskette in A Press any key when ready...

The above errors are mostly caused by the loss of CMOS information caused by the lack of CMOS power supply or the type of "C:" is not set.

These are just some common reasons for hard disk bootstrap failures. If it is category 1, 3, you can manually eliminate it, if it is a type 2 problem, it is difficult for yourself to start, it is best to go to the factory or hire a professional to repair it.

7. Snatch valuable hard disk data from death

The accident originated from a power outage. I was sorting out my hard drive at that time. As power outages often occurred on university campuses, I was used to it and didn't pay much attention to it. After the power supply is restored, the computer is started, but the system shows that there is no system disk, prompting to insert the boot disk. I habitually took out the win98 boot disk and started the system, thinking that it was just another simple system file corruption that could be easily fixed. But things came as a surprise to me. After the system starts, type "C:", and the system prompt shows that the current directory is already in the root area of C disk, but DOS reports an error when I try to list the directory structure. Run Scandisk and report that it may be a BIOS setting error or a virus. Exit. The entire c disk looks as if it has not been formatted and cannot perform any operation. To make matters worse, all the rest of the divisions were lost! Fdisk can only show disk C and its capacity (the same size as before the accident-which is important, as will be mentioned below), and the rest of the partitions, along with their hard disk capacity, are missing. Thinking of a recent article that a sudden power outage may cause errors in BIOS's hard drive settings, I unhurriedly restarted my computer and entered BIOS to set up my hard drive, but I didn't find any errors! The problem is much more serious than we thought. At this time, I was a little sick and confused, and hurriedly found articles about hard disk failures for reference. I even suspected that I had been hit by a virus or a hard disk lock, but it was not very consistent from the point of view of the phenomenon. and because there is important data saved in the hard disk, I usually pay attention to strict prevention of viruses, basically can rule out this problem. There is no information on hand to mention this kind of problem, it seems that my question is still very unique, "unprecedented" ah. Now I have to rely on myself and rely on my own strength to save my valuable information.

Coincidentally, I happen to have a Norton2002 CD on my desk (there may be a lot of old birds who have been in contact with Symantec's Norton8.0 since the DOS era, and since then Norton series software has helped us solve countless computer hardware and software problems, and it can be said that the most professional system diagnosis and maintenance software is unyielding). Why not try to see if it can help me tide over the difficulties again?

Just do it, remove my hard drive and install it on my roommate's computer and set it correctly. Start Win98 to install Norton2002, and can't wait to run Norton disk doctor scan hard drive (Norton components support FAT16, FAT32, NTFS, which are the most commonly used partition formats), and immediately NDD will find hard disk partition errors and some professional "inexplicable" errors that can not be understood, and then, of course, fix these abominable problems. After restarting, I was surprised to find that the files on disk C had been fully restored, not a single bit less, and won the first battle.

But how to recover the data in the rest of the partition? I was a little overwhelmed, but now I can tell for sure that it wasn't the virus and the hard drive lock, thanks to the fact that there was no random drugging at that time. Recall that NDD fixed more than one error when testing the hard drive, and may now have recovered the lost capacity. When I thought of this, I typed in "Fdisk". As expected, I found all the lost hard disk capacity. The next step is to repartition and format? It's not that simple. in that case, my information may go to heaven and never get it back. How can I give up what I have collected hard for many days? Hasn't disk C been restored? Why don't I "clone" several "identical C drives" and ask NDD to restore my hard drive? Use Fdisk to partition the rest of the hard drive (my hands tremble a little due to certain risk factors). It is important to note that the new partition must be exactly the same as the original partition, and if you can't remember, you may have to give up. After dividing the zone, go back to Win98 and run NDD to check the partition (never format the partition). Like disk C at that time, NDD found the error and successfully repaired it, and all the data in the partition were recovered, which made people ecstatic.

The solution to the problem all depends on Norton, so I can't help but be impressed by it again. Do not need to master advanced knowledge, do not need cumbersome operation, Norton can give your system to the most professional maintenance, when your system has a variety of inexplicable errors, with the help of Norotn may be able to achieve twice the result with half the effort. Why don't you try it, my friend?

8. Can the low frame eliminate the bad path of the hard disk?

A: let's talk about what to do if something goes wrong with the hard drive. I heard that using low-level formatting can solve the problem and make the hard drive "reborn"? Is that what happened?

B: low-level formatting should not completely eliminate the bad path of the hard drive. To put it simply, the current low-level formatter will only shield the physical bad path of the hard disk, but can not fix it. After the hard disk has been "low-grid" processing, the bad path may not be seen, but that is only to hide the bad path. And if the next time there is a bad way to do another "low", such a vicious circle, there will only be more and more bad ways! Although it is not on the surface, more and more sectors are shielded, and there will be less and less free space on the hard disk! By the time you really wake up, it may be beyond the warranty period, and it's too late to repent! It is better not to advocate this practice.

C: but most of the bad roads are only logical. "low grid" can be repaired completely, and it can be used normally after repair. I have used such a hard drive.

B: the bad logic needs to be repaired with "low case"?

C: of course! That is the most direct way, with other software can also!

B: but did you know that when the Lformat program finds a physical bad path, it will prompt an error and quit, and it is impossible to complete the repair work! Besides, since it is certain that it is a logical bad way, it is OK to use NDD. Using LFormat is simply "drinking poison to quench thirst"!

D: is LFormat really useful? The answer is no! That is only a measure of rights and interests, it may be able to make the hard drive barely use, but there will not be any complete repair theory, and it is only an isolated case! In addition, manufacturers generally provide a 3-year warranty period, so it is better to send it back to the manufacturer for replacement or maintenance if it is within the warranty period.

B: I personally think that low-level programs are designed for manufacturers, not ordinary users. There are many people want to use "low grid" to repair when they see their hard drive has bad track, which is possible in theory, but what is the nature of hard disk bad track that plays a decisive role? If it is a physical injury, it is useless to use a "low box" 100 times, because the hard disk is not a "mud block". Just rub it when there is a crack. Therefore, before the "low grid", we must clearly distinguish the nature of the bad Tao, if we blindly use the low-grid program, it will only be counterproductive.

In addition, the low-grid program will delete all the original partitions, but the bad roads still exist, and when you partition again, the original bad paths may be divided into two or more. Although it may not be seen for the time being and cannot be detected by the system for the time being, the bad channel will expand and spread like an infectious disease. If there is important data stored in the sector where there is no problem for the time being, it will be miserable once it happens! From my personal experience, the hard disk with physical bad channel does not make low grid, and the spread speed of bad channel is slower than that of low grid, and even if it spreads, it is only in the adjacent sector of bad channel, but after using low grid, it may blossom all over the ground!

And I remember that many manufacturers have warned users to be cautious about using "low grid"! I'm afraid that's what the intention is.

D: in fact, we should first distinguish the types of bad Tao and confirm whether it is logical bad Tao or physical bad Tao.

B: if you have to use Lformat to "fix" bad ways, you should first know what is Servo, what is ECC, what is Preamp, and what is PRML? And as ordinary users should also know, the current hard disk does not have any third-party programs to do the real sense of "low-level formatting."

C: after you have talked for a long time, I still don't know what is physical bad Tao and what is logical bad Tao. Does it mean that what software can repair is logical bad Tao, and what cannot be repaired is physical bad Tao? The "physical bad track" reported by software such as Scandisk only refers to an error that the hard disk returns to the operating system when writing instructions to the hard disk, while the logical bad channel refers to marking a bad channel on the FAT table, but the corresponding position of the FAT table can read and write normally. Is that what happened?

B: by bad logic, I mean that the hard disk is accidentally disturbed while writing, resulting in an ECC error. When the hard disk is written, it will reassemble the data with the logic of ECC. In general, the operating system needs to write 512 bytes, but in fact, the hard disk will write dozens of bytes, and all these bytes have to be encoded in ECC. If the ECC calculated from the original byte is different from the ECC calculated from the read byte, an ECC error will occur, but the data can generally be read at this time.

The physical bad track refers to the media damage of the disk or the inability to read or write to an area caused by various reasons.

D: in fact, there is a difference between soft and hard in physical evil. The physical damage on the surface of the medium is hard and can not be repaired. However, due to some external influence caused by several bit errors in data writing, the general operating system will also think that it is a physical bad path, but this bad path can be modified with the hard disk's own logic or the software provided by the factory. although the general format or the so-called "low grid" program will report errors in these locations, this kind of ECC error can be corrected and written back correctly with corresponding instructions and logic.

In addition, even if the hard disk has individual minor surface physical damage, the current hard disk can be corrected by redirecting the sector to a good reserved sector, as the data guard of the WD hard disk does.

In fact, all hard drives have an internal "table" in which there are some physical addresses (located by Servo logic and offset represented by real physical track representation). These locations indicate that writing data in these places may be unstable or have minor defects, and this "table" is called P-List.

The formatting instructions of the operating system generally call the write sector or format sector instructions of ATA, which cannot complete tasks such as correcting ECC errors or sector redirection. Therefore, general formatting or hard disk correction software can not modify this kind of error that can be modified.

C: there is a question to ask: whether the real "low grid" is no longer something that the end user can do, because because of logical addressing, the programs used by the end user can not carry out the original "low grid". In a sense, it is just a more advanced hard disk logic reset operation than the original "low grid". Therefore, I think it doesn't make much sense to talk about "low grid" now. at present, some hard disk companies have also provided Zero-Fill (zero filling, filling the whole hard disk with 0 characters) tools, the surface effect is actually similar to "low grid". What do you think?

In addition, many hard drives now have their own Defect List, is this what you call P-List? At the same time, does this also mean that these hard drives also have sector redirection technology?

D: today's hard drives all have this "redirect" technology. To put it simply, it is to map the real CSH to a "table" on a virtual CSH. You should be used to a hard disk with only one head that has 16 heads in the setting, and these things are indeed in a reserved partition and can be accessed through a normal ATA interface.

However, if you want to enter this reserved partition, the hard drive must first enter the state of abnormal use (we call it Native mode), and also know the offset of each "table" and the data structure of the "table". Therefore, for a large piece of data that may be tens of megabytes, but does not know the data structure and the beginning and end of the "table", users cannot use it even if they know it, let alone modify it. (Flying Bird 2000 collects and collates)

Summary of this issue: the topic of this issue revolves around whether a friend can repair the hard drive with a "low grid" program. With regard to the "low grid" problem, the main opinions are: if there is physical damage to the disk, it cannot be completely solved unless it is replaced; if it is not physical damage, it depends on what is going on here, and some can be solved by ordinary users, such as using Format or the LFormat mentioned in the article; but there are other soft problems that only manufacturers have relevant tools to solve.

9. Complete strategy for data rescue of faulty hard disk

In order to effectively save the data in the hard disk, in addition to regular backup work, it is also necessary to learn how to save the hard disk when the hard disk fails, or to extract useful data from bad areas to minimize the loss.

The system does not recognize the hard disk

The system cannot be booted from the hard disk, nor can it be booted from disk A to disk C, nor can it be booted using the automatic monitoring function in CMOS.

The presence of the hard drive was found. This kind of fault mostly occurs on the connecting cable or IDE port, and the failure of the hard disk itself is not likely. The replacement test can be carried out by replugging the hard disk cable or changing the IDE port and cable, and the fault will be found quickly. If the newly connected hard drive is not accepted, a common reason is the master-slave jumper on the hard disk. If two hard disk devices are connected to an IDE hard drive cable, it is necessary to distinguish the master-slave relationship.

Failure caused by CMOS

Whether the type of hard disk in CMOS is correct or not directly affects the normal use of hard disk. Today's machines support the "IDE Auto Detect" function, which can automatically detect the type of hard disk. When the hard disk type is wrong, sometimes the system simply cannot be started, sometimes it can be started, but a read and write error occurs. For example, if the hard disk type in CMOS is less than the actual hard disk capacity, the sector behind the hard disk will not be able to read or write, and if it is a multi-partition state, individual partitions will be lost. There is also an important reason for the failure, because the current IDE supports logical parameter types, the hard disk can use "Normal,LBA,Large" and so on, if the data is installed in the general mode, and the CMOS is changed to another mode, there will be a hard disk read and write error failure, because the mapping relationship has changed, will not be able to read the original correct hard disk location.

Startup failure caused by master bootstrap

The master boot program is located in the main boot sector of the hard disk, which is mainly used to check the correctness of the hard disk partition and determine the active partition, and is responsible for handing over the boot power to the DOS or other operating systems of the active partition. The damaged program will not be able to boot from the hard drive, but the hard drive can be read and written after booting from the floppy or optical drive. The method to fix this fault is relatively simple, and it is most convenient to use FDISK with a higher version of DOS. When running with parameter / mbr, the main boot program of the hard disk will be replaced (rewritten) directly. In fact, the main boot sector of the hard disk is established by this program, and the FDISK.EXE contains a complete hard disk master boot program. Although the DOS version is constantly updated, the main boot program of the hard disk has not changed. From DOS 3.x to Windos 95 DOS, as long as you find a DOS boot disk to boot the system and run this program, you can repair it.

Startup failure caused by partition table error

Partition table error is a serious error of the hard disk, different degrees of error will cause different losses. If there is no active partition flag, the computer cannot start. However, after booting the system from the floppy or CD-ROM drive, the hard disk can be read and written, and the active partition can be repaired by resetting the FDISK.

If it is the wrong type of partition, it can cause the loss of a partition. The fourth byte of the partition table is the partition type value, the normal bootable basic DOS partition value greater than 32MB is 06, while the extended DOS partition value is 05. Many people use this type of value to implement the encryption technology of a single partition, and the partition can be restored to normal by restoring the original correct type value.

There is also other data in the partition table to record the start or end address of the partition. The corruption of these data will cause confusion or loss of the partition. The available method is to rewrite back up the partition table data, or to obtain the partition table data from other hard drives of the same type and in the same partition condition.

The recovery tool can use NU and other tool software, the operation is very convenient. Of course, DEBUG can also be used for operation, but the operation is tedious and has certain risks.

The fault of the partition valid flag error

There is also an important part of the main boot sector of the hard disk, and that is its last two bytes: "55aa", which is a valid symbol of the sector. When booting from a hard disk, floppy disk, or CD, these two bytes are detected, and if present, the hard disk is considered to exist, otherwise the hard disk will not be recognized. This can be used for the encryption technology of the whole hard disk, and the DEBUG method can be used for recovery processing. In addition, when there is no boot flag in the DOS boot sector, the system boot will be displayed as "Mmissing Operating System". The convenient way is to use the following common fixes for DOS systems.

Startup failure caused by DOS Boot system

DOS boot system is mainly composed of DOS boot sector and DOS system files. The system files mainly include IO.SYS, MSDOS.SYS and COMMAND.COM, in which COMMAND.COM is the shell file of DOS, which can be replaced by other similar files, but it is a necessary file for DOS startup by default. In the DOS system carried by Windows 95, MSDOS.SYS is a text file that is necessary to start Windows, but this file is not needed when only DOS is started. When there is a DOS boot error, you can use the SYS C: command to transfer the system after booting the system from the floppy disk or CD, and the fault can be repaired automatically, including the boot sector and system files.

Read and write failures caused by FAT table

The FAT table records the storage address of the hard disk data, and each file has a set of FAT chains that specify the cluster address where it is stored. The corruption of the FAT table means the loss of the contents of the file. Fortunately, the DOS system itself provides two FAT tables, and if the currently used FAT table is damaged, you can use the second one for overwrite repair. However, because the length of the FAT table of different specifications of the disk and the address of the second FAT table are not fixed, the correct location must be found correctly when repairing. Some tools, such as NU, have such repair functions, and it is also very convenient to use. This can also be done with DEBUG, which uses its m command to move the second FAT table to the first table. If the second FAT table is also damaged, the hard disk can not be restored to its original state, but the data of the file is still stored in the data area of the hard disk, which can be repaired by CHKDSK or SCANDISK command, and finally get the .CHK file, which is the sector data of the lost FAT chain. If it is a text file, the full or partial contents of the file can be extracted from it.

Boot failure caused by catalog table damage

The catalog table records data such as the file name of the file on the hard disk, the most important of which is the starting cluster number of the file. The catalog table does not have automatic backup function, so if the directory is damaged, a large number of files will be lost. One way to reduce the loss is to use the CHKDSK or SCANDISK program recovery method to search for .CHK files from the hard disk. Because only the first cluster number is lost when the directory table is damaged, each * .CHK file is a complete file, and most of the files can be restored by changing it to its original name.

Recovery of data when partitions are mistakenly deleted

When you delete the hard disk partition with FDISK, it appears that the data in the hard disk has completely disappeared, and entering the hard disk will appear as an invalid drive when it is not formatted. If you understand how FDISK works, you will know that FDISK only rewrites the contents of the main boot sector of the hard disk. Specifically, it deletes the partition table information of the hard disk, while the data of any partition in the hard disk has not changed. You can copy the error repair method of the partition table mentioned above, that is, find a way to restore the partition table data and restore the original partition and data. If the partition has been formatted, after restoring the partition first, you can restore the partition data as follows.

Recovery of mistakenly formatted hard disk data

In the DOS high-version state, FORMAT formatting operation in the default state is used to restore formatted disk information, in fact, the disk DOS boot sector, FAT partition table and catalog table of all the contents of the copy to the last few sectors of the disk (because the latter sectors are rarely used), while the contents of the data area has not changed at all. This can be restored by running the UNFORMAT command. In addition, DOS also provides a MIROR command to record the information of the current disk for recovery after formatting or deletion, which is also more effective.

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