Abstract: A method and apparatus for detecting and recovering from head instability in a magneto-resistive (MR) transducer head of a disc-drive system. A head-instability-recovery circuit is described for use in disc drive to recover from a head-instability condition of an MR transducer head. This circuit includes a controller and a current source that supplies current to the MR head. The current source is controlled to supply a nominal amount of current to the MR head when operating in a normal mode, and to supply one or more current bursts having a current above the nominal supply current in order to recover from the head-instability condition. Also described is a method for recovering from a transducer-instability condition of an MR transducer of a disc drive, including detecting a situation that indicates a head-instability-recovery operation is desired, and performing the head-instability-recovery operation.

Abstract: Apparatus for detecting defect in a recordable medium such as a disc drive is disclosed. The apparatus includes a recording system which write and read test data on the medium. The apparatus also includes a first comparator for comparing the read data to a first threshold. A first and a second counter, operably connected to the first comparator, are incremented when the read data exceeds the first threshold. When the first counter obtains a first count value, a first defect signal is produced. Data domains associated with the recordable medium are marked as bad in response to the first defect signal. When the second counter obtains a second count value, a second defect signal is produced and data sectors associated with the recordable medium are marked as bad in response to the second defect signal. A method for detecting defects in a recordable medium is also disclosed.