ADRS Advisory and Price Guide – Hard Drives

Skilled Hard Drive Data Recovery is usually contained within the scope of five disciplines, as listed below:

1. Logical Failure: The data is inaccessible, yet the drive appears to be functional.. One instance may be when the hard drive has been erroneously formatted or the file table is now corrupted. In addition, if a "System Recovery" has been performed from a manufacturer’s supported scenario, then it is mandatory the PC must be shut down. Immediately and directed to a professionally skilled recovery source.. With continued use of that unit, the data will be usually be overwritten (for example with temporary internet files) and your personal data will be lost permanently!

2. Media Issues: Where the drive has developed bad sectors, making it difficult or impossible to access via any Windows based operating system. This can be most commonly diagnosed by the fact that the hard drive is seen correctly in the BIOS (i.e. Correct Model number and capacity) and the computer locks up (freezes) when you try to access the drive. In this case a sector-by-sector image of your entire drive must be cloned onto a good drive, and then specialized software must be employed to extract the data from this image. We utilize specialized cloning modalities, including DeepSpar Disk Imager, costing thousands of dollars which use combinations of soft/hard resets of the drive, as well as powering the drive down if necessary, to ensure the best possible image of the faulty drive;

3. Electronic Failure: Where the logic board (PCB) has failed or died. This can be most commonly diagnosed by a completely dead drive, burning smell or making clicking noises. In this case a perfectly compatible PCB has to be located to re-enable access to the drive. This is NOT a simple matter, as nearly all drives have ROM (Mainly WD & Seagate) or NVRAM (IBM/Hitachi) information programmed into the PCB itself. This information has to be cloned to a file, then re-programmed into the donor PCB. This requires special hardware & software, again costing many thousands of dollars, to accomplish this. In some models, such as Toshiba laptop drives, this ROM info is absolutely unique to the drive and so the original PCB must be repaired to facilitate the recovery. We have surface mount and hot-air soldering for this purpose. Also, the electronic failure has may have caused partial media problems (bad sectors), so an image needs to be made and worked from cases where the Growing Defect List (G-List) has also been damaged and/or corrupted (see above Category 2 failure);

4. Firmware Failure: This occurs when some modules of "firmware" on the actual platters of the drive have become damaged/corrupted. The drive requires these modules to the read from the Service Area (SA) of the drive, before it will start up and become available. This may manifest itself by the drive spinning as normal and sounding OK, but is inaccessible in the PC's BIOS. It may be seen as its factory alias (e.g. "Athena" for some Maxtor drives, or "HAWK" for some WD models). To recover from this requires extremely specialist hardware and software (such as from ACE Laboratories or Salvation-Data), plus years of experience and technical knowledge to repair the SA. This activity mandates skill and resources (such as replacement modules from compatible stock/library drives), as one small error can render your drive irrecoverable. Also, the firmware failure may have created partial media problems (bad sectors), so an image needs to be made (see above Category 2 failure), especially in cases where the "G-List" (Growing defect list) has been damaged or corrupted;

5. Physical Failure: Here, a physical fault is preventing your drive starting up. This can range from a single failed head, through complete head stack failure, to motor failure. A single head failure can be diagnosed when the drive ID's OK and starts to image well, but in patches (e.g. The Deep Spar Imager may image 150,000 sectors perfectly, then 50,000 inaccessible, and so on. In this case 1 of 4 heads have failed). A complete head stack failure usually signals by clicking from the drive when it is started up. If your drive clicks at all then DO NOT UNDER ANY CIRCUMSTANCES continue to try and access it, or put it in the freezer (an "old wives tale" that WILL almost certainly destroy your data permanently.  In the case of head failure, your drive needs to be disassembled in a Class 100 Clean Room and the offending heads removed. The replacement heads must be fitted and not to be undertaken by unskilled personnel. Anyone can buy a Cleanroom and claim to be a "Data Recovery Specialist", but it takes years of training and practice to be able to perform this procedure skillfully and successfully. Replacement heads are also often very difficult to locate due to compatibility issues, so substantial resources and vast product knowledge is required. In the case of motor failure, this is usually shown by the drive not spinning up at all, or making a quiet buzzing sound. In most cases, a motor failure requires the heads and platters to be removed and placed into a wood working chassis. Once more, great skill, techniques and specialized equipment required to do this. Finally, the failure may have also caused partial media problems (bad sectors), so an image needs to be made and cloned (see above Category 2 failure);

 More common operational failures by Manufacturer:

Toshiba - Head Failure (clicking), Motor Failure (not spinning or rattling noises)
Hitachi - PCB failure (dead), Head Failure (loud clicking)
WD - PCB (dead or clicking), Head Failure (loud clicking), SA Failure (spinning up but not seen in BIOS)
Seagate - Head Failure (quiet clicking), Motor Failure (Not spinning and quiet "Buzz buzz buzz" sound)
Maxtor - Firmware Failure (Seen incorrectly in BIOS), Head Failure (clicking)
Samsung - Head Failure (Clicking), PCB (dead)