As it happens, modern hard drives tend to be more fragile than their predecessors. You can find lots of people using their decade-old Pc’s, with 80GB Western Digital or 40GB Samsung drives. Those drives were made to withstand the test of time.
At present, we see a great decrease in the life span of mechanical drives. With growing capacities and cutting edge technologies, such as SMR, Hybrid or Helium drives, the amount of things that can go wrong grows as well.
Today I want to talk about "burnt drives." A burnt drive is a hard drive that was subjected to a power surge, which resulted in damage to one or more of its electrical systems.
What can cause a power surge?
In most cases, that would be a sudden spike in the grid, caused by a lightning storm or malfunction with the PC’s power supply, although many other events could result in damaging the hard drive, starting from the degradation of the PCB (Printed Circuit Board), bad soldering, poor quality of components, moisture or a user error. Whatever the reason is, once the currents start to rise, they bring high temperatures. And once it’s high enough, a component subjected to those temperatures will burn.
How would you identify a burnt drive?
First of all, the smell and the smoke. Burned electrical parts smell like burned plastic, and that would be the first sign of the damage that occurred.
Visual inspection – The PCB can be easily removed from the hard drive. Upon removal, the burnt parts will be spotted in plain view.
Drive performance – Burnt drive will not spin and will not power on.
What happens to the PCB and the drive once it’s faced with a power surge?
Most of the modern PCBs are equipped with temperature sensors designed to monitor the PCB temperature, protective diodes built to shield the drive from power surges and capacitors used to flatten the line of the incoming voltage. Those components serve well, and often they "sacrifice" themselves to save more crucial components of the PCB.
Unfortunately, if the power surge is too powerful, it often damages some of those crucial components, before being terminated.
Often, the damage is extended beyond the PCB and affects a small chip located on the actuator arm of the read/write heads. That small chip is called a preamplifier or preamp. It will result in permanent damage to the read/write heads assembly, and will probably require to have it replaced.
The Printed Circuit Board
To begin with, let us talk about the role of the PCB. It serves as an interface between the data stored on the platters and the computer. It transfers data in and out, controls the operation of the drive, provides power (5V and 12V), and stores some unique information as per the drive. The main components of the Printed Circuit Board are:
MCU – Micro Controller Unit. It would usually be the biggest chip onboard the PCB. The MCU serves as the central processor of the hard drive, controls the flow of the data, and converts digital data coming into the hard drive into analog signals for the read/write heads, and vice versa.
VCM – Voice Coil Motor Controller. In charge of controlling the movement of the heads and the rotation of the spindle motor. The VCM controller is built to withstand high temperatures, as it consumes and transfers the majority of the power used by the HDD. Usually, it also one of the first components to burn out.
The ROM – This little chip is called ROM (Read Only Memory) in professional jargon, but it functions more like an EPROM (Erasable Programmable ROM) – it means that it’s contents can be erased and reprogramed. It contains a very important part of the drive’s firmware, and without it, the drive would not function properly. The part of the software contained within the ROM is unique to the drive it’s installed on. That is why if you are looking to repair your drive by installing a new PCB instead of a burnt one, your drive will not resume its normal function.
Sometimes, you will see PCB’s without the ROM chip. That means that the data usually contained by the ROM is embedded in the MCU.
What can you do when your PCB sustained irreversible damage
As we can derive from the explained above, simply replacing the PCB for a new one won’t cut it. The data contained in the ROM of an old PCB must be transferred onto the new donor PCB, to have the drive working.
That can be done in one of the following ways:
When attempting any DIY solution, one must always consider the risks involved. On one side, it feels great to accomplish a complicated repair, not to mention the nice side effect of saving some time and money. On the other side, there is always a chance of causing additional damage up to the level when even a professional data recovery specialist won’t be able to help. Over the years, I had seen cases when clients damaged the ROM chip by overheating it or by breaking one of its legs, and when that happens, there is no way back. Yes, for some WD models, you can potentially rebuild the ROM, but if you have a Seagate or Hitachi, the chances to ever see your data are extremely slim.
If you decided to attempt your repair, please consider the outcomes. If you cannot afford to lose your data, perhaps it’s better to let a data recovery company handle it.
Start the process now. Contact us for a free evaluation