Patent ID: 7715139
Filing Date: 2010-05-11
Classification: G11B

Abstract:
1. A method for testing a magnetic disc device, comprising at least: writing data on every other track of the magnetic disc according to a servo pattern; writing data on the rest of the tracks; reading data from all tracks in which data are written; determining whether a read error occurs; determining a track having a deviation of a track pitch based on the read error; arranging that data is written on a track in which a read error occurs, and no data is written on tracks surrounding the track in which the read error occurs; starting reading of data from a position away from one side of the track, and sequentially reading data at some positions, each of which is gradually closer to the track; obtaining a first position where an error rate of reading the data reaches a predetermined error rate; starting reading of data from a position away from the other side of the track, and sequentially reading data at some positions, each of which is gradually closer to the track; and obtaining a second position where an error rate of reading the data reaches a predetermined error rate, wherein a position of the track is calculated based on the first position and the second position.