Important Basic Knowledge For Physical Hdd Data Recovery


Mechanical hard drive is the highest degree precision computer mechanical component, its internal cleanliness is cleaner than10 clean environment. HDD is driven by a high-speed motor to rotate counterclockwise, the voice coil motor powers drive heads for read and write operations on the platter.

At work, Hard drive is floating 0.02 microns on the disc with the help of air flow, this distance is less than one percent of the diameter of a human hair, in which case any severe vibration may cause head crash and platter damage. Once the head is damaged, it can not correctly identify the magnetic information on the disk.

Because the head and the platter are so sophisticated components, their working environment must be extremely clean. When hard drive is working, a speck of dust can be as devastating as a bomb on platter.

The hard disk drive HDA contains four main modules:

* Motor: to spin the platter at certain speed.
* Platter: the most important part where the data is saved on.
* Heads assembly ( includes Head, Arm, Voice Coil and Controller Chip ). This is the R/W part of HDD that reads and writes data on platter.
* Magnet: Give power to Arm.

Among the four, heads assembly and motor are movable parts that are more easily broken. If they are damaged, you have to open drive and change them to recover data.

Head is the read/write part on the HDD, while motor rotates the platter in high speed. Head and motor are extremely high degree precision mechanical parts, comparing to other electronic components within the hard drive, they can fail more. Any improper handling may result in damage to the head, here are some common head breakdowns.

1. Normal aging: Head aging and cannot identify the info on the platter.
2. Abnormal aging: Due to design defects or production defects, head has abnormal aging.
3. Severe impact: a very small distance is between head and platter when working, head can crash into platter because of severe impact.
4. Drop: Dropped from desktop, head will crash into platter/parking ramp.
5. Accidental power failure: Voice coil can pull head back to parking ramp all of sudden that can damage head.
6. External damage: flooded, burnt.

A working HDD will read firmware first from SA when powering on. After checking and loading firmware, HDD is standby for read/write operations. When HDD is damaged, it will not be able to read SA so that HDD itself will keep trying that causes abnormal noise. Some drives will stop trying when reading servo failed after several attempts.

Here are some most common HDD faults symptoms. All of these symptoms indicate your drive has physical damage that you should power off the HDD. Do not keep trying using the HDD that it can damage platter.

1 Bluescreen, show 0x00000077 0x0000007A 0x0000007. Bad sectors or firmware can also show similar info.
2 BIOS cannot detect HDD when powering on.
3 Tick tick sound.
4 Beep warning sound
5 Power on and not spinning. PCB failure
6 Spin up and spin down.

What you should NOT do

1. Keep restarting HDD. Many people would try to restart PC/HDD over and over again to see if it can be fixed. Do not do this as keep powering head damage drive can scratch platter.
2. Force copy data. It can make things worse when forcing data copy/read when you hear abnormal sound from HDD. This can damage platter too.
3. Open HDD yourself. Never try to open HDD by yourself especially in a normal environment. This can destroy data permanently.

What you should DO

1. Power off HDD immediately. This will prevent further platter damage.
2. Handel damaged HDD with care.
3. Call to professional data recovery company.