Hard Drive Recovery: Parts of a Drive & Tips on Reacting to Failure Symptoms

By Steve George

September 10, 2019IT Equipment

Everyone, at some point in their life, has lost some valuable piece of data they couldn’t get back. Whether it was a picture, a Word document, a PowerPoint presentation, or anything similar, it probably gave you a ton of stress. Now, can you imagine losing all of your business data due to hard drive failure or something bigger? It can potentially set your business back significantly and cost you tons of money and downtime. Nowadays, hard drives have become much more complex, simply because they’re more powerful in terms of their ability to store huge amounts of data. What this means is that simple hard drive recovery methods may no longer be as effective as they used to be just a few years ago.

That being said, in order to get a better understanding of why hard drives usually fail nowadays, you need to explore the mechanisms of a hard drive, so that you can also get a better idea of what hard drive recovery approach to take. Most of the time, the best approach to hard drive recovery is seeking out a professional data recovery service. The only time you can tackle the issue yourself is if the hardware corruptions are slim, you have the right software and the hard drive is still readable by the operating system.

Every hard drive, including traditional and contemporary ones, consist of a few basic parts, such as platters, a read-write head, a printed circuit board, firmware and a working mechanism that ties it all together. Let’s explain all of these parts in more detail.

The platters of the hard drive are usually made with aluminium and are coated with magnetic material. This part is the main source of saving your digital data and running it on your operating system/computer. Platters spin at rates of about 5000 to 7000 RPM (sometimes more) depending on the capacity of the drive. Further, every platter can feature sectors, tracks, and cylinders that define the structure in which the digital data is stored. Since the platters are coated, they may wear over time, which can freeze up the hard drive when the reading sector is damaged.

hard drive recovery

The read-write head, as its name suggests, is responsible for reading the data. Every platter has at least two heads, and modern hard drives have 6 or more heads as they contain at least 3 platters. These heads “fly” over the platter and read the data at high speeds by moving around the platter. All heads are attached to a so-called actuator arm that’s responsible for moving the head around the platter and makes sure the heads don’t come in direct contact with the platter, as that might damage it. Above or below every platter is a copper wire that’s a part of the head, and it can magnetize or demagnetise to save or delete data. A failing head won’t read the data from the platter, or it can make the hard drive invisible on your computer’s BIOS. This can be a result of a power outage, overage, etc.

The printed circuit board (PCB) is responsible for providing electricity of all other parts and converting the digital data into readable data. Since it’s connected to the power source directly, this part is arguably the most vulnerable part and prone to failing or burning immediately without any indicators. However, it’s also the one that’s most easily replaceable if you know how to open the hard drive in a safe environment.

Then, there’s the firmware, which is basically the code responsible for initiating the hard drive as you power up your computer. It also “commands” what each and every part should do and part of it is stored on the printed circuit board. Naturally, as is the case with most software, many things can go wrong with the firmware, and corruption or damage can be hard to deal with. Damage or corruption of the firmware should be addressed with the utmost care, and by someone who knows the ins and outs of hard drive recovery processes.

Lastly, the purpose of the working mechanism is to find an empty area on the platter (blocks or sectors) write data on it, and store the unique directory location of that data on the master file table so that it’s kept there even after you turn off your PC. This allows the data to be accessed when necessary and to ensure that the read-write head doesn’t overwrite it. When you want to access that data, the CPU will send information to the hard drive and tell it about the request. The hard drive will then located the data in a matter of nanoseconds and revert back to the CPU with the found data.

So how does recovery software actually recover data after files are deleted? Well, even after deleting data, there’s a directory record maintained by the master file table and a cache of the data, even though space may be marked as free and overwritten when new data is saved on the hard drive. Most recovery software works the same way. As soon as you start the hard drive recovery process, a program will pop up and initiate a scanning process in order to get information from the master file table about any deleted data. Worth knowing is that overwritten files can also be recovered, but that will depend on the amount of data you’ve saved after deleting that data.

Some of the most common symptoms of a failing hard drive are your system failing to start-up or weird noises start coming out the hard drive with a black screen or an error message, the platter stops spinning due to a printed circuit board failure, or freezes once you try to access or save data. If any of these problems occur, it’s best you stop using your computer and take a look at the root of the problem. If you’re knowledgeable, you may perform this yourself, but it’s always recommended that you leave it to a professional recovery serviceperson.