Common Problems and Diagnostics of Seagate data recovery.

U Series 5
Typical problems with this drive family are diode failures which affect the voice coil and spindle, and failure of the read/write channel.

Barracuda ATA II
This family tends to suffer from problems with the stabilizers of the spindle motor circuit either by burning or shorting out. The latching transistors of the read/write channel circuitry, the symptoms of which are the drive produces knocking at a frequency of 5Hz.