Circle Hook Data Recovery offers diagnostic services at no charge.


Diagnostics are always done with an objective in mind. That objective is to find out if we can access your important stuff. You will need to meet with David or Richard to tell us what that is. The objective is not to find out why your computer can't access your data. That can be a very time-consuming process, and sometimes we can only narrow the causes down to a few candidates. What is important is the data.


What happens during diagnostics?

During diagnostics we do not attempt any procedures that could further damage the drive. For example, we don't swap circuit boards simply because we have one from the same model, and we don't loosen or remove the hard drive's cover. This is because there is one cover screw that goes through the head stack assembly, and drives are sensitive to the tension produced by this screw. Although a drive can be opened safely in our clean room, we do not do this during the initial diagnostics phase. Consequently, all of our procedures are external to the drive at this stage.


The objective of our diagnostics is to find out whether or not any of the files that you identified as being important are accessible. We do not focus on finding out why your drive failed; we focus finding out if the important files can be accessed.


 If you don't have any important files that you want recovered, or if you have them backed up, then you don't need diagnotics and you don't need data recovery. It also isn't for you if you want your drive repaired. Data recovery does not result in a drive that has been repaired and can be used again. 


At the lab, diagnostics begins with using a data recovery tool to look at the file system directory. Are the names of the files visible? If they are, then are the files intact or are they corrupted? If they are intact, can they be read? If they can't, is it because the data is incoherent or is it because some of the data sectors are not being read? Is this due to a problematic read head? Or is there platter damage? 


To confirm platter damage, the drive would need to be opened, and even then - apart from the top surface of the top platter - it is impossible to see all the platter surfaces because they are closely stacked. As mentioned above, we will not open the drive to look for platter damage during diagnostics.


If we can't see the names of your important files in the file system directory, then we will use a data recovery tool to attempt to recover the directory. Often, physical (i.e. hard-to-read sectors) and logical damage (i.e. corruption) occur in the file directory. This is an area of high drive activity: reads and writes occur frequently here.  


After enough of the file system directory has been recovered, we again look for the names files of primary importance. If their names are visible, then we will try again to access them.


What if the drive seems to be spinning, but makes clicking noises and cannot be seen by your computer?


In most cases, this is caused by one or more broken read heads. When a read head is broken, no data can be read from its platter side until a new read head can be installed. 


Other hardware malfunctions include damage to the circuit board, such as broken connectors, traces, or circuit elements. Hardware damage inside the drive consists of damaged magnetic read heads, damaged preamplifiers, and stuck spindle motors. Sometimes, a read head is stuck to a platter.


Firmware malfunctions involve the operating system of the drive. A hard drive has many features in common with a computer. It has an operating system which is independent of the operating system of the computer, it has RAM (i.e. volatile solid state memory), NV-RAM (i.e. non-volatile solid state memory), and a microprocessing unit. A drive contains its operating system code in chips on the circuit board and on an area of the platters called the service area. The firmware contains information about vital drive parameters, for example, where bad sectors exist, and what kinds of electromechanical corrections must be done to bring the drive up to specifications. This information is unique to the drive. When this code is corrupted or cannot be loaded, then the drive will not advance to the ready state - a state where data is visible and can be accessed.


A common problem is read head degradation. If there is degradation to the read heads - which can occur if a drive is dropped or has experienced age-related degradation - we will try to coax them to read better by temporarily (and harmlessly) instructing the drive to spend more time trying to read the data sectors, or to make additional read attempts before giving up. If this fails, then we have two choices: the head stack assembly will need to be replaced with one from a closely matching drive, or we can try to determine if the files of interest where written wholly or largely with a single write head, allowing them to be read with a single, working read head.



The purpose of diagnostics is to find out if we can recover the data that is important to you.