    AST RESEARCH, INC.        TECHNICAL BULLETIN # 1722          05/20/97

    TITLE:  RF Gasket Installation Precautions

    ISSUE

       When installing a third-party peripheral device into one of the
       external drive bays, the device's circuit board may be shorted
       out if the installer is not careful when attaching the RF gasket
       to the device. This could result in damage to the device or the
       computer.

       Some peripherals examined have little or no clearance between the
       device's circuit board and the top or bottom edges of its frame.

       This issue applies to any system shipped with accessory RF
       gaskets.

    BACKGROUND

       It is sometimes necessary to attach conductive RF gaskets to
       devices when installing them into external drive bays on some
       systems.  RF gaskets ensure Electro-Magnetic Interference (EMI)
       does not exceed acceptable levels for the FCC-type acceptance for
       that particular system.

       AST ships the necessary RF gaskets for systems requiring them in
       the accessory kit included with that system.

    ACTION

       To ensure that the circuit board will not short out, follow the
       procedure outlined below.

       NOTE: Perform this procedure BEFORE applying power to
       the system to avoid equipment damage.

       Carefully inspect for sufficient clearance between the RF gasket
       and the device's circuit board, after installing it into the
       external drive bay. It is important to perform this visual
       inspection after installing the device into the computer.
       Adjacent devices and blank filler panels will tend to compress
       the gasket down onto the device.

       If a clearance issue is detected (or suspected), the installer is
       responsible for ensuring that the device's electronics are
       properly insulated from the gasket.

    NOTES

       Failure to follow this procedure may void your system's warranty.

    TAN TPR 2032MH

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