    AST RESEARCH, INC.        TECHNICAL BULLETIN # 1138           7-12-96

    TITLE: Ascentia 9XXN Hard Disk Vibration

    SUMMARY

       The Ascentia 9XXN system may experience vibration.

       This issue affects all Ascentia 9XXN systems uSing Quantum 500MB
       hard disk drives, part numbers 230126-500 and 450006-003.

    ISSUE

       The Ascentia 9XXN system may experience a very pronounced vibration
       when the hard drive is spinning.

    BACKGROUND

       Faulty Quantum 500MB hard disk drives part numbers 230126-500 and
       450006-003.

    ACTION

       If the Ascentia 9XXN system is experiencing very pronounced
       vibrations when the hard drive is spinning, and the hard drive is
       a Quantum 500 MB, return the system to an AST Authorized Service
       Center for a hard disk drive replacement.

    NOTES

       This modification should be performed ONLY by a qualified service
       technician.  It is strongly recommended that this change be
       completed by an AST Authorized Service Center.  In no case will
       AST Research, Inc. be liable for damage to the system and its
       components, or loss of data caused by improper modification.

       AST recommends a full backup of all data on the hard drive in the
       computer.

       Refer to the system Hardware Maintenance Manual.

       Removal and replacement of system "Field Replaceable Units" (FRUs)
       should only be performed according to the installation procedures
       approved and prescribed by AST Research, Inc.

       To verify proper operation of the system upon completion of this
       change, follow the setup and test procedures described in the
       AST User's Manual.

       Warranty reimbursement for this change requires prior
       AST Research, Inc. approval.

    TAN 003658RH

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