WD hard disk platter scratched into a "ring runway" data recovery

The equipment of Tiangong Technology can be widely used in various data recovery laboratories, data analysis institutions, education platforms, big data room, command and dispatch center, multimedia data center and many other scenarios. It is the designated data source recovery technology “efficiency source technology”. Equipment appearance supplier. The following is the specific application of the "Data Analysis All-in-One ED-MD9200" in the efficiency source technology data recovery service.

Equipment Name: Data Analysis Machine ED-MD9200

Function introduction: It adopts aluminum-magnesium alloy casing, military quality, and automotive paint process to design a rugged analytical equipment; the product adopts 21-inch multi-touch display, no need for external control equipment; multi-interface integrated integrated technology design, Ensure that the device connection is more convenient and the overall layout is more coordinated; support I7/I5/I3 processor configuration and SSD solid state drive to ensure efficient data processing; device special physical read-only interface, which can greatly improve the data analysis process Security and normative.

Equipment pictures:

[Editor's note: At the beginning of this period, the topic of "hard disk opening" entered the second phase, and the efficiency source engineers continued to explain the "opening data recovery method for the Western Digital hard disk scratch into a 'ring runway'." In the first issue, the "fault detection" method of the case disk (Western 2TB hard disk) was introduced in detail, and the importance and operational difficulties of the "opening" were emphasized. In this issue, we will focus on another important data recovery operation after the opening of the disk - "change the head", repair the hard disk by this method, and try to recover the hard disk data. 】

A magnetic head refers to a component that reads data on a magnetic medium by electromagnetic principles. Common magnetic heads include hard disk heads, tape recorder heads, and the like. The hard disk head is the key component of the hard disk reading data. Its main function is to convert the magnetic information stored on the hard disk disk into an electrical signal for external transmission. The working principle is that the resistance value of the special material will follow The principle of the change of the magnetic field is to read and write the data on the disc. The quality of the magnetic head determines the storage density of the hard disk. The specific structure is shown in Figure 1:

[Figure 1 The magnetic head is an important part of the hard disk hardware]

1, the actual combat object: Western Digital 2TB hard drive, SATA interface, as shown in Figure 2 (appearance is intact, no obvious signs of falls):

2, hard disk preparation (3 physical disk)

(1) Recovery disk A: There is a failure, and the data to be extracted is stored.

(2) Mirror disk B: mirror copy data, post-analysis

(3) Parts plate C: Replace the magnetic head (the same model and same batch as A)

3, failure phenomenon: the first night of normal use, power off, the next day connected to the computer, the hard disk is not recognized, and accompanied by abnormal knocking.

4, the cause of the failure: the initial test of the efficiency source engineer, the hard disk head is damaged, the disk has serious scars (before the delivery, the hard disk is repeatedly energized, causing damage), this is the reason that the hard disk is not recognized. Specifically, as shown in FIG. 3, A is a normal disc, B is a scratch disc (a case of a hard disk disc), and a white circle of "circular runway" appears in the middle, and the degree of scratching is "disastrous." The figure A is the effect of correcting the processing into a normal disk on the basis of the B picture to compare the degree of scratching of the disk.

[Figure 3 hard disk platter is severely scratched (B)]

5, data recovery:

After the cause of the malfunction is determined, the right medicine can be prescribed and the data recovery link is officially entered. First of all, it is necessary to solve the "head failure", if the head can be read normally after replacing the head, the recovery work is successfully completed. If it doesn't work, because the platter is too severe, and there are other hidden faults that are not found yet, you need to add other solutions.

(1) Replace the magnetic head: continue to replace the magnetic head of the accessory disk C with the recovery disk A (head matching) in the double-level dust-free working chamber, as shown in Fig. 4, which takes about half an hour. It is important to note here that the replacement of the head must be very detailed, as each small jitter can have a serious impact on the final data recovery result.

[Figure 4 The replacement head must be in a dust-free environment (this figure is mainly to show the real world of the replacement head, the hard disk in the figure is not the Western Digital hard disk in this case, but the Seagate hard disk in other cases)]

(2) Power-on test: After completing the most complicated head replacement work, a simple power-on test, normal seeks occur, and data recovery has made breakthrough progress. However, the head stopped unexpectedly after normal seek.

(3) Re-energization test: The engineer repeatedly considers each operation process and determines that there are no omissions and mistakes, and then decides to re-energize the test. At this time, it was found that the head was normal when reading the firmware information, but the operation was stopped after the reading was completed. This indicates that the hard disk can access the firmware area normally and has the basic conditions for data extraction.

(4) Prepare the data mirror: cover the hard disk cover, leave the double-level dust-free studio, and prepare to extract data. At this point, you need to prepare the recovery disk A, mirror disk B, DRS data recovery system.

(5) Connect the DRS data recovery system: Connect the recovery disk A to the DRS data recovery system, listen carefully to the sound, stop the motor after the hard disk seeks, and the image cannot be started.

There is a difference between the working sound of the magnetic head and the bad working sound before the replacement. It is judged by experience that the magnetic head should read some firmware, but the hard disk still cannot be started normally. The efficiency source engineer analyzes and discusses this phenomenon, which may be related to the scratch of the disc. The head stops operating because it encounters a scratched area. I decided to try the "hot plate change" method, directly change the firmware of the recovery disk A and the normal disk, and extract the data by "stealing the beam".

[Editor's note: According to the efficiency source engineer, the head fault is one of the typical symptoms of hard disk hardware failure, such as head wear, dirty head contact surface contamination, head swing arm deformation, head shift, etc. Generally, after the power is turned on, the sound of the head movement is obviously abnormal, the hard disk cannot be detected by the system BIOS, and the partition cannot be partitioned or formatted. The "changing the head" is an effective method. Using the magnetic heads of the same batch and the same type of normal hard disk, the faulty magnetic head is replaced to achieve normal starting. However, the head failure generally causes the disc to be scratched. For example, in this case, the hard disk is very scratched, and changing the head is only one of the steps. The engineer added another technology "hot plate change" to succeed. The specific operation method of "hot plate change" will be introduced in detail in the next issue, so stay tuned!]