Abstract: A device for measuring a magnetic property of a magnetic reproducing head at a measurement point thereon, the device which applies a first magnetic field which oscillates at a predetermined oscillation frequency to the measurement point, applies a second magnetic field of which strength changes slower compared with the oscillation frequency of the first magnetic field to the measurement point, detects a signal generated by the magnetic reproducing head according to the total strength of the first magnetic field and the second magnetic field, extracts amplitude components synchronizing with the oscillation frequency from the signal, and calculates changes of the signal against the total magnetic field strength based on the extracted amplitude components.

Abstract: A circuit and method are presented for detecting a fault in a magneto-resistive head (18). The circuit includes a bias circuit (50) to produce a bias voltage across the head (18) and a pair of resistors (68,70) in series with the head (18) connected to the bias circuit (50) to carry a current (IVMR) from the bias circuit (50) in common with the head. A circuit (102,102′) is provided to determine a ratio of a voltage across the head (18) with respect to a voltage across the head (18) and the pair of resistors (68,70), and a circuit (104,106,104′,106′) is provided for indicating a fault if the ratio falls outside a predetermined range.

Abstract: Methods and devices are provided that allow heads for use in disk drives to be tested in a helium environment in a cost-effective way with little or no impact on test time and with minimal consumption of helium.

Abstract: A method is described for calculating head disk interference (HDI) using a dynamic parametric test. In one embodiment, HDI is calculated based on an actual and ideal sensitivity profile based on a read-back signal track profile for the slider/head.

Abstract: An automated production process for the screening of the read-width (RW) and/or the stripe-height (SH) for every magnetoresistive (MR) read sensor element in a wafer substrate. The method of this invention uses the RW and/or SH values found with optical examination by electron microscopy of several of the MR sensor elements to estimate two substrate coefficients that relates the optical RW and SH measurements to heating-delta measurements, &dgr;=(RH−RC)/RC, where RH is the sensor resistance when hot and RC is the sensor resistance when cold, both of which can be measured using automated equipment. These relationships are sufficiently similar among all MR sensor elements manufactured on a single wafer substrate during a single manufacturing procedure that, when the hot resistance RH is measured at a constant applied voltage, the heating-delta, may be used with a first substrate coefficient to estimate the read-width RW of each MR sensor element for quality-control purposes during manufacture.

Abstract: A method of connecting a plurality of probe pins to a plurality of first external connection pads, which are provided on a head gimbal assembly and are electrically connected to a plurality of terminal electrodes of a write magnetic head element, respectively, and a plurality of second external connection pads, which are provided on the head gimbal assembly and are electrically connected to a plurality of terminal electrodes of a read magnetic head element. In the connection method, an approach direction of the probe pins to the first external connection pads and an approach direction of the probe pins to the second external connection pads are made different from each other.

Abstract: A magnetic head and disk tester comprises a base, a spindle for rotationally supporting a magnetic disk, a carriage for supporting a magnetic head support which carries a magnetic head with a magnetic read/write element, and a dual-stage positioning system that moves the carriage in two perpendicular directions X and Y. The magnetic head support, the magnetic head and the magnetic read/write element have a common longitudinal axis Z. The head support is positioned such that the longitudinal axis Z forms a predetermined angle between 0° and 90° with respect to the Y direction. Preferably the predetermined angle is about 45 degrees. When the head is driven from one point of an inner track to a point of an outer track, the displacement of the head along X axis is relatively large and the displacement of the head along Y axis is relatively small.

Abstract: A write precompensation amount setting method and apparatus comprise a function detecting the respective head characteristics with an electric current used at an ordinary temperature and a irregular electric current, and a function setting an optimum write precompensation amount at a low temperature according to the detected head characteristics.

Abstract: The magnetic head tester of the present invention drives a medium (40) for rotation to float a slider (10) from the medium (40) so as to test a magnetic head for its characteristics, and the tester comprises a holder (20) removably holding the slider (10) opposed to the surface of the medium (40), and suspension means (24) provided in the holder (20) which has the same function as a suspension supporting the slider (10) in a real apparatus. With this tester, tests can be executed by exchanging the slider (10) alone, and it is unnecessary to discard the suspension even when the magnetic head is judged to be out or order, thus loss of production cost for the suspension and processing cost for assembling the slider in the suspension can be avoided.

Abstract: A magnetic head testing apparatus includes reference information storing means for holding a predetermined reference sampling period and a number of reference samplings, sampling means for sampling reproduced data read a plurality of times from a magnetic medium in the reference sampling period, sampling number acquiring means for acquiring a sampling number of measured data from a reproduced data base on a sampling result, sampling number radio calculating means for calculating a ratio of the sampling number of the measured data and the number of reference samplings, sampling data re-acquiring means for changing the sampling period of the measured data depending on the calculated ratio and re-acquiring the sampling data and a measured data overlap-displaying means for overlap-display of the sampling data re-acquired from the measured data a plurality of times.

Abstract: A PTP test subsystem of a magnetic disk drive identifies an undesired pole tip protrusion (PTP) condition, and takes steps to prevent problems associated with PTP. A PTP stressing mechanism stresses the disk drive during a PTP test mode to induce a PTP condition. A disk contact detection circuit detects when a head of the disk drive contacts the disk. A PTP write current determining circuit is also provided which comprises a write current level detector to ascertain a write current level at which the disk contact detection circuit detects when the head of the disk drive contacts the disk while the disk drive is stressed during the PTP test mode.

Abstract: A novel magnetic imaging microscope test system with high spatial (1-10 nm) and temporal (˜1 ns) resolution of the magnetic field is disclosed, as well as the system application for characterization of read and write heads for magnetic recording. The test system includes a scanner assembly and a work piece holder for holding a work piece to be tested. The scanner assembly and the work piece holder are positionable relative to each other at very fine resolution during scanning. A probe arm is cantilevered from the scanner assembly to bring a probe head into close proximity to the work piece holder. The probe head is configured scan a work piece in contacting engagement therewith so that a magnetic device on the probe head magnetically interacts with a magnetic field generating or magnetic field sensing device on the work piece. A probe head for use in the test system and a related test method are also disclosed.

Abstract: A preamplifier circuit of a preamp configured for measuring microwave noise of a magnetoresistive element biased by a pair of current sources is disclosed. In a preferred embodiment, the preamplifier circuit includes a differential amplifier disabled from the preamplifier circuit by a amplifier bypass switch, one of the pair bias current sources disabled from the preamplifier circuit and referenced to ground by a current bypass switch, a test point communicating with the amplifier bypass switch providing single ended access to the biased magnetoresistive element for measuring the microwave noise of the biased magnetoresistive element relative to the ground reference and a ground point communicating with the ground reference providing the ground reference for measuring the microwave noise of the biased magnetoresistive element.

Abstract: A first read gap layer has a resistance RG1 between a first shield layer and one of the first and second lead layers of a read head and the second read gap layer has a resistance RG2 between a second shield layer and said one of the first and second lead layers of the read head. A connection is provided via a plurality of resistors between a first node and each of the first and second shield layers wherein the plurality of resistors includes at least first and second resistors RS1 and RS2 and the first node is connected to said one of the first and second lead layers. A second node is located between the first and second resistors RS1 and RS2. An operational amplifier has first and second inputs connected to the first and second nodes respectively so as to be across the first resistor RS1 and has an output connected to the first node for maintaining the first and second nodes at a common voltage potential. In a first embodiment the first and second shield layers are shorted together.

Abstract: A magneto-resistive device with built-in test structure. The magneto-resistive device includes a slider having first and second lower termination pads and first and second upper termination pads. A first conductive trace element electrically couples the first lower termination pad to the first upper termination pad and a second conductive trace element electrically couples the second lower termination pad to said second upper termination pad. The magneto-resistive device also includes a magneto-resistive transducer deposited on the slider and the resistance of the magneto-resistive transducer is obtained by passing an electrical current between the first and second lower termination pads and measuring a voltage across the first and second upper termination pads.

Abstract: A structure is integrated into the design and manufacture of a magnetic head that allows self-generation of magnetic fields. The structure includes a conductor or conductors placed in close proximity to the read portion of a magnetic head and connected to an externally accessible connection. A high frequency signal is passed through the conductor to generate a magnetic field through the read device and simulate, for example, the head crossing magnetic domains on a magnetic memory disk.

Abstract: A test system and method determining performance of a merged magnetoresistive read-write head based upon operating the write inductive head of the merged read-write head, measuring the resistance of the read head under certain read current bias conditions and finding which read heads have been damaged by ESD.

Abstract: Probes are electrically connected to a surface of a tunnel junction film stack comprising a free layer, a tunnel barrier, and a pinned layer. Resistances are determined for a variety of probe spacings and for a number of magnetizations of one of the layers of the stack. The probe spacings are a distance from a length scale, which is related to the Resistance-Area (RA) product of the tunnel junction film stack. Spacings from as small as possible to about 40 times the length scale are used. Beneficially, the smallest spacing between probes used during a resistance measurement is under 100 microns. A measured in-plane MagnetoResistance (MR) curve is determined from the “high” and “low” resistances that occur at the two magnetizations of this layer. The RA product, resistances per square of the free and pinned layers, and perpendicular MR are determined through curve fitting.

Abstract: A method and computer program to calculate a reproduction track width of a MR head. This method begins by subdividing the magnetic domain control layer of a MR element and lead conductors into several polyhedral elements. Thereafter, electric potentials are calculated for each of the polyhedral elements based on the resistance at each layer. A current density is determined for each of the polyhedral elements based on the calculated electric potentials. The current densities are integrated to calculate an initial resistance value. Further, the resistance of a local block is changed by a predetermined amount. The electric potential is calculated for each of the polyhedral elements, current density is acquired, and the acquired current densities is calculated to determine a resistance value. Finally, the reproduction track width is obtained based on the initial acquired resistance value and the acquired resistance value.

Abstract: A process, computer program product, and apparatus for detecting and quantifying crosstalk instability in a read/write mechanism are provided. A write current is varied in a write circuit for exciting the write head. Measurements are taken of a magnetoresistive impedance of a read current of a read circuit. Measurements are also taken of a signal amplitude in the read circuit. A bit error rate of the overall system is also measured. The read/write mechanism is failed if the signal amplitude changes by a predetermined amount during the varying of the write current. Likewise, the read/write mechanism is failed if the error rate changes by a predetermined amount during the varying of the write current. The write-to-read signal coupling of HGA (Head Gimbal Assembly) and HSA (Head Stack Assembly), including GMR sensor, suspension and flex cable on the actuator arm, can be evaluated at component design level. The methodologies successfully simulate GMR cross talk instability inside a drive on magnetic testers.

Abstract: A method of analyzing characteristics of a magnetic transducer includes sub-dividing a region to be analyzed in a magnetic transducer into a plurality of polyhedral elements, and performing a transient calculation. The transient calculation includes calculating a transient electric field of each polyhedral element, calculating a transient magnetic field of each polyhedral element, and updating the magnetic permeability in accordance with a magnetic flux density determined from the calculated transient magnetic field. The steps of performing transient calculation are repeated until a predetermined number of time steps have been completed, in order to determine electric fields and magnetic fields of all of the plurality of polyhedral elements in the region to be analyzed.

Abstract: A structure is integrated into the design and manufacture of a magnetic head that allows self-generation of magnetic fields. The structure includes a conductor or conductors placed in close proximity to the read portion of a magnetic head and connected to an externally accessible connection. A high frequency signal is passed through the conductor to generate a magnetic field through the read device and simulate, for example, the head crossing magnetic domains on a magnetic memory disk.

Abstract: A testing apparatus for a magnetic head or a magnetic disk, includes a magnetic disk; a magnetic head moving mechanism which holds a magnetic head and which moves the magnetic head to a predetermined position in a radial direction of the magnetic disk; a movement mechanism control device for driving the magnetic head moving mechanism, wherein the movement mechanism control device moves the magnetic head moving mechanism to a predetermined radial position corresponding to position data; a read/write control device for writing a predetermined magnetic signal on the magnetic disk using the magnetic head, and for reading a magnetic signal of the magnetic disk using the magnetic head; and a memory for storing therein position data embedded in a data surface of the magnetic disk, extracted from the magnetic signal which is read by the read/write control device. A testing method is also disclosed.

Abstract: An apparatus and associated testing method for identifying void heads in magnetic storage systems in which a first bit error rate is determined using data written at a first overshoot amount. A second bit error rate is determined using data written at a second rate current in a second overshoot amount. A physically damaged transducer head is identified based upon a comparison of the first bit error rate to the second bit error rate.

Abstract: A method for non-destructive measurement of dynamic coercivity is disclosed. In this method, magnetic media is DC erased by applying a forward DC magnetic field to the magnetic media such that the magnetic moments in the magnetic media are substantially aligned. A specified number of reversed magnetic field pulses are then applied to the magnetic media in a direction opposite to the forward DC magnetic field, wherein the intensity of the reversed magnetic field pulses is less than the remanent coercivity of the magnetic media. The broadband medium noise of the magnetic media is measured. The intensity of the reversed magnetic field pulses is then repeatedly and incrementally increased and applied to the write head for the specified number of pulses, the intensity of the reversed magnetic field pulses eventually exceeding the remanent coercivity of the magnetic media. For each intensity level of the reversed magnetic field pulses, the broadband medium noise is again measured.

Abstract: A magnetic tape drive apparatus in which data are recorded/reproduced on/from a magnetic tape by recording/reproducing magnetic heads which are disposed on a head drum and moved on a circular locus comprising cleaning device for removing deposit such as stain adhering to a magnetic head to clean the magnetic head, error rate detection device for detecting the error rate of the magnetic tape when data are recorded/reproduced onto/from the magnetic tape, and error rate storage device for storing the error rate detected by the error rate detection device, wherein the error rate detected by the error rate detection device exceeds a reference error rate by a predetermined amount, the magnetic head is cleaned by the cleaning device.

Abstract: A method of determining a magnetic track width of a magnetic head. The method begins by obtaining a full track profile of the magnetic head which includes a plurality of signal amplitudes read across a track of a magnetic disk at a plurality of magnetic head positions. An initial magnetic track width value is then determined from the full track profile data. Preferably, this initial value is the magnetic write width which is determined based on the difference between left and right head positions which read half of the maximum signal amplitude. To determine the final magnetic write width, the initial value is adjusted with side reading correction values. The side reading correction values are determined based on left and right side reading “tails” of a bell-shaped signal curve which is formed by the full track profile data when graphed. It is not necessary to obtain the microtrack profile to determine these side reading values.

Abstract: A magnetic head that includes a magnetoresistive effect read head element is tested by applying a varying magnetic field and measuring the resulting output signals from the read head element. The output signals are digitized and a processor calculates, e.g., the root mean square (RMS) of the signals or performs a Fast Fourier Transform or Autocorrelation on the data to determine if there is noise present. If desired, write and delay events may be performed prior to digitizing the output signals from the read head element to determine if additional noise, which is introduced to the magnetoresistive head from the write element, is present. In one embodiment, the digitizer may be replaced with an RMS meter.

Abstract: A method is disclosed for determining the presence of response abnormalities in magnetic sensors. The method includes placing the sensor in an applied magnetic field and collecting sensor resistance information as the magnitude and direction of the applied field is altered. The resistance values are then examined to determine the presence of response abnormalities.

Abstract: A magneto-resistive device with built-in test structure. The magneto-resistive device includes a slider having first and second lower termination pads and first and second upper termination pads. A first conductive trace element electrically couples the first lower termination pad to the first upper termination pad and a second conductive trace element electrically couples the second lower termination pad to said second upper termination pad. The magneto-resistive device also includes a magneto-resistive transducer deposited on the slider and the resistance of the magneto-resistive transducer is obtained by passing an electrical current between the first and second lower termination pads and measuring a voltage across the first and second upper termination pads.

Abstract: A magnetic head wear-rate measuring apparatus for measuring the rate of head wear in noncontact form arranged to be opposed to a magnetic head and to serve as a part of oscillating elements of an oscillator circuit. A magnetic resistance of a magnetic circuit at a rotational position where the magnetic head faces the magnetic sensor, changes according to the degree of extension of the magnetic head from the surface of the drum, and the change in magnetic resistance acts as a variation in oscillating frequency. A counter is supplied with a pulse of a measured oscillating frequency and produces a pulse having a pulse width up to the counting of a predetermined number of pulses. The counter output is supplied to a second counter where the number of reference clocks lying within the pulse width is counted and used as measured data.

Abstract: There is provided an apparatus and method for controlling a disc drive and, more particularly, an apparatus and method for restoring stability to a head of a hard disc drive, so that instability in a magneto resistive (MR) sensor of the disc drive can be restored through an electric shock. Instability of the MR head, i.e. incorrect alignment of the domain of the MR head, is determined by a bit error rate (BER) test and channel statistical measurement (CSM) test, and instability of the MR head is determined, the MR head is restored by applying electric shocks thereto. Therefore, the apparatus and method have advantages in that manufacturing process inferiority rate due to instability of head in a hard disc drive can be reduced, yield can be improved and the defect rate can be improved.

Abstract: A scanning magnetic microscope includes a specimen stage for holding a specimen to be examined; a sensor for sensing a magnetic field generated by the specimen, the sensor including one of a magnetic tunneling junction (MTJ) sensor, a spin valve sensor, or an extraordinary Hall effect sensor; translation apparatus for translating the sensor relative to a surface of said specimen; and a data processor, having an input coupled to an output of said sensor, for constructing an image of said magnetic field. In another embodiment a read/write head from a hard disk drive is shown to make a suitable magnetic sensor. The scanning magnetic microscope can be used for examining the current flow in integrated circuits and related phenomenon, such as electromigration, as well as magnetic data storage media and biomagnetic systems, to mention a few suitable applications.

Abstract: A writer coil in a data head of a data storage system is tested by coupling detection circuitry to the writer coil and driving the writer coil with a periodic pulse signal generated by the detection circuitry. As a result, voltage is generated, with the detection circuitry, as a function of an inductance of the writer coil. An inductance of the writer coil is calculated as a function of the generated voltage. Electrical short circuits and discontinuities in the writer coil are identified as a function of the calculated inductance.

Abstract: A method for magnetically measuring the magnetic read width (MRW) of magnetic recording heads having a track width that is equal or smaller than the wavelength of visible light is provided. The heads comprise a magnetic read head spin valve sensor and the magnetic read head sensor signal is used to derive an unknown track width from comparing to the sensor response of a known track width. Using this method, track widths in the regions at the wavelength of light and below (<500 nm) can be directly measured without destroying the respective sensor material.

Abstract: In a magnetic head measuring apparatus for measuring a magnetic head, an amplitude-modulated electric current whose amplitude is modulated by a specified carrier wave frequency and modulation frequency is applied to a magnetic head. A calibrating magnetic field generating source causes the magnetic head to generate a magnetic field having a specified strength and frequency, thereby calibrating measurement variations of the magnetic head. A magnetic head measuring device measures a high-frequency magnetic field generated from the magnetic head. If necessary, an interchangeable magnetic material probe is used to replace a probe of the magnetic head measuring device.

Abstract: An apparatus and associated testing method for identifying void heads in magnetic storage systems in which a first bit error rate is determined using data written at a first overshoot amount. A second bit error rate is determined using data written at a second rate current in a second overshoot amount. A physically damaged transducer head is identified based upon a comparison of the first bit error rate to the second bit error rate.

Abstract: A device and method for testing a slider of a head-gimbal assembly during disc drive manufacturing. The device includes a test disc, an actuator arm and a control module. The test disc has a first circumferential area for detecting contact between the slider and the test disc and a second circumferential area for burnishing sliders that contact the first circumferential area as the test disc rotates at or above the predetermined velocity. The head-gimbal assembly is affixed to a support, or flexure, on the actuator arm such that the slider is operable to move between an inner diameter and an outer diameter of the test disc. The control module controls rotation of the test disc and movement of the actuator arm, and thus the slider, relative to the test disc. The control module monitors the slider-disc interface for contact therebetween. If contact is detected, the slider is either burnished or the head-gimbal assembly is discarded altogether.

Abstract: A test system and method determining performance of a merged magnetoresistive read-write head based upon operating the write inductive head of the merged read-write head, measuring the resistance of the read head under certain read current bias conditions and finding which read heads have been damaged by ESD.

Abstract: A method for improving the operational performance of a disc drive through the identification of vital product information associated with a head-disc assembly (HDA) of the disc drive. The disc drive comprises a printed wiring assembly (PWA) housing control circuitry for the disc drive. The HDA of the disc drive is operably coupled to the printed wiring assembly and includes a rotatable disc to which data are written by a controllably positionable head. A non-volatile memory device is mounted on the HDA and operably coupled to the PWA so that, when the disc drive is initialized, the PWA verifies the configuration of the HDA before proceeding with the initialization of the disc drive, thereby preventing errors and damage to the disc drive as a result of the installation of a new, replacement PWA in the disc drive, or the downloading of new, incorrect firmware to the PWA.

Abstract: A magnetic head measuring apparatus executes measurement with respect to at least one measurement point on a recording head. The apparatus includes a probe having a magnetic substance, a vibrator which vibrates the probe above the at least one measurement point, a first signal generator which supplies a drive signal to the vibrator, a second signal generator which supplies a current containing a direct current and an alternate current to the recording head to generate a magnetic field from the recording head, a detector configured to detect a signal corresponding to a force interaction that acts on the probe due to the magnetic field generated from the recording head in accordance with the current supplied by the second signal generator, and a measurement unit which measures current dependence of the magnetic field of the recording head from the signal detected by the detector.

Abstract: A method and apparatus to qualify heads to be used in disc drives. The method and apparatus collect a set of track scan data by moving the head across transitions in a track on a medium. The track scan data is changed based on a difference between a writer width of the head and a nominal track width to produce modified track scan data. Position error signal data is then determined from at least some of the data in the modified set of track scan data. The linearity of the position error signal data is used to qualify the head.

Abstract: The invention includes methods determining the presence of base line popping noise for a read head inside an assembled disk drive, as well as, determining read bias conditions for operating the read head free of base line popping noise. The invention further includes performance evaluation of the read head for read bias conditions free of base line popping noise. The invention also includes repairing the read head using DC write current and read bias current within the assembled disk drive.

Abstract: An apparatus for measuring a characteristic of a specimen, includes a probe for scanning a surface of the specimen in a noncontacting state, a vibrating unit for vibrating the probe, an excitation field generating unit for generating an amplitude modulation signal which is amplitude-modulated with a modulation frequency and a carrier frequency and producing an excitation field at the surface of the specimen on the basis of the generated amplitude modulation signal, and a measuring unit for measuring a force interaction between the probe and the specimen caused by the excitation field generated at the surface of the specimen.

Abstract: The invention includes a method and apparatus repairing read heads of a merged magnetoresistive read-write head without the use of external magnets nor the exclusive use of read bias current to heat the read head.

Abstract: An optical apparatus and methods for efficiently determining the magnetization of a material at very high optical resolution are disclosed. Individual components of the magnetization may be determined. Components in the plane of the sample surface are imaged by illuminating the material obliquely with substantially parallel light of relatively high power and very well controlled uniformity and polarization, and using light scattered obliquely in a parallel beam in the opposite direction at the same angle as the angle of incidence to record an image. Reversing the illumination and observation directions allows subtraction of the two images and measurement of the magnetization in-plane. A second in-plane component orthogonal to the first, is obtained similarly after reorienting the plane of incidence 90 degrees.

Abstract: A method is disclosed for determining the presence of response abnormalities in magnetic sensors. The method includes placing the sensor in an applied magnetic field and collecting sensor resistance information as the magnitude and direction of the applied field is altered. The resistance values are then examined to determine the presence of response abnormalities.

Abstract: A method and apparatus for using control apparatuses and read/write apparatuses within a disc drive to create a microtrack that is used to probe the magnetic sensitivity of each portion of a magnetic stripe of a magneto-resistive read/write head in the disc drive. The method can be executed by first selecting a target track and then recording a test signal along the target track. Next, the target track is trimmed to create a microtrack, the microtrack having a microtrack width less than the stripe width, the microtrack having a first circumferential edge and a second circumferential edge. Subsequently, the magneto-resistive stripe is positioned at various radial locales traversing the microtrack, and at each locale the magneto-resistive stripe is used to read the test signal recorded on the microtrack, thereby producing a detected signal at each of the various locales. Finally, a signal-strength profile is determined.

Abstract: A paddle board with flexible extended leads is provided. The paddle board includes a chassis and a flexible lead portion. The flexible lead portion has wire traces disposed therein for receiving a plurality of wires from a parametric test head. The paddle board may be connected to a socket of a testing assembly for testing the performance of a batch of storage media. The paddle board reduces the amount of damage or breakage to the wires extending from the testing head.

Abstract: An apparatus and associated method for attaching a disc drive cover member to a disc drive base member. A fixture comprises a base and a stop guard, cradle and guide rails supported by the base. The disc drive base member is operatively receivingly engaged in the cradle adjacent the guide rails. The disc drive cover member is operatively abuttingly engaged at one end against the stop guard and pivoted toward the disc drive base member. Any substantial misalignment of the disc drive cover member with the disc drive base member causes the disc drive cover member to engage at least one of the guide rails and therefore be urged into proper alignment, preventing adverse contact between the disc drive cover member and the disc drive base member.