The most common symptom of the failure of the PCB electronics , ( see picture) , of a Hard Drive is that it simply receives no power.

Most drives I receive with failed PCB’s have died due to faulty power and commonly this is due to the age of power adapters on portable hard drives.

Hard drive PCB’s have over voltage protection on them which is designed to fail so as to protect the motor and heads.

Repair Process

•         Confirm that the PCB actually needs to be replaced. If the drive does nothing when powered on or shuts off intermittently,                 the      PCB may be at fault.
•         Locate a suitable replacement PCB.
•          Purchase a replacement PCB.
•          Transfer BIOS chip from failed PCB
•          Connect the replacement PCB. Test and transfer data to new drive.

On some hard drive models eg Western Digital and Seagate the transfer of the ROM chip from the failed hard drive electronics to a working PCB is not possible. This is due to the fact that there is not a separate 8 pin chip containing the ROM on the PCB. Modern Western Digital hard drives have the ROM firmware located in the Main Controller integrated circuit of the PCB , see pictures below.
The pcb on the right does not have the ROM Chip and will require specialzed tools to perform the ROM transfer. Here at dig_IT we use the Salvation Data Hard Drive doctor suite to perform these transfers.