HDD electronic failure

Data recovery in cases of PCB (electronic) failures:

The role of Printed Circuit Board – PCB of any hard disk is to provide hard disc with constant power supply and to provide connections with motherboard controller.

On early HDD, PCB min and only function was to provide continuous power suplly. All control logic was on special cards (called controllers), plugged into the PC. As a consequence, controllers were generalized, since they had to work with different models of hard drives. That didnt represent a problem in and of itself, since all hard drives were similiar back then, as well as their characteristics. With the development of microelectronics and micromechanics, disk drives had more possibilities, as well as greater speed, so control logic was moved to the drives themselves, that is to their PCB. From that time is the acronym IDE (Integrated Drive Electronics).

Todays PCB have all the elements of early computers, processor, EEPROM, RAM, controllers, and safety circuits. All those elements are needed to enable us to use higher densities of the media, different spindle rotation speed, and faster reading and writing speed of modern drives.

Some of the PCB functions are:

  • Spindle controll, making sure that its rotation speed is as declared
  • All reading/writing operations
  • Actuator positioning on disk cylinders
  • Continuous power supply
  • Address translation
  • Disk internal cache memory
  • On newer USB drives, data encryption chip

Most common PCB malfunctions are:

  • Burnt safety circuit and processor
  • Burnt spindle driver chip
  • Malfunctioning actuator (although technicaly its a part of disk mechanics, the connection between processor and comutator results in damage to both parts)
  • Contact oxidation on delicate connections between comutator and drive motor
  • ROM corruption


While first two malfunctions are easily diagnosed (hdd doesnt start at all, and he does not produce any sounds), third malfunction is harder to diagnose.

ROM coruption can manifest in different ways, and symptoms are similiar or same to symptoms of other malfunctions, including mechanical hard drive failures or service area corruption.

The most common mistakes people make when they are faced with malfunctioning hard drive, is to assume and conclude its a PCB malfunction. Next step, they try to replace disk electronics from a disk which is similiar or same as the drive they had. Since PCB control logic has unique elements native to the drive which it belongs, by starting the drive, the mechanics of their drive starts to work using the parametars of the other drive. That can lead to media damage potentionaly, especially damage to the service area of the disk, making data recovery impossible.

Data Solutions Laboratory experts posses both knowledge and experience necessary to repair and reconstruct damaged ROM, as well as bypass and repair malfunctions on damaged PCB, and gain data access. Usually, in most cases regarding electronic failure, it is possible to make a clone (identical copy) of the disk, on a disk brought for recovered data.


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