Because of this customized firmware, however, it's not possible to switch out a PCB board in many cases; of course, this varies depending on the manufacturer of a drive. For instance, some older drives have the same basic information on two PCB boards of the same model, provided that both drives were made at about the same time, before more unique adaptives were programmed into the next line of drives. If one of the PCBs fails, there is some chance of making a recovery by simply swapping the boards of the two drives. However, hard drives have contained "customized" firmware on at least an occasional basis since they've become a consumer product, so the chances of a straight "board swap" working are very low. In addition, because of the unique adaptives, it is highly possible to damage a drive further by the placement of a foreign PCB. Data recovery companies must rebuild the firmware information in many situations when the PCB of a drive fails. In addition, occasionally PCB failures cause damage to other hard drive components, such as the heads of the drive (and subsequently the platters, in certain situations). Professional data recovery companies have special processes to treat these problems as well.
If you think that your hard drive has a problem with its PCB board, it's important that you don't try to operate the drive any further or try switching out the PCB board with another drive's. Get your hard drive to a reputable data recovery company immediately for an evaluation.
A good data recovery company will be able to quickly diagnose the drive's issues and let you know what your options are from that point. http://www.onepcbsolution.com/ http://www.youtube.com/watch?v=du0Qd_3wFWM