    =

    AST RESEARCH, INC.         TECHNICAL BULLETIN # 1204                 6-6-95

    =

    AST DESKTOPS NOT RECOGNIZING ADD-ON BOARDS

    PROBLEM

    AST desktop systems may fail to recognize the modem, the ISA adapter, or
    other add-on boards.

    CAUSE

    The capacitor connected to the signal line 'RSTDRV'inhibits proper transfer
    of the ISA reset signal.

    SYSTEMS AFFECTED
    AST PART NUMBER AND DESCRIPTION

    501533-XXX          BRAVO P-60
    501534-XXX          BRAVO P-90
    501535-XXX          BRAVO MS FAL
    501543-XXX          ADVANTAGE! RMS P/60
    501544-XXX          ADVANTAGE! RMS P/90
    501545-XXX          ADVANTAGE! RMT P/60
    501546-XXX          ADVANTAGE! RMT P/90
    501613-XXX          BRAVO MS P-90
    501650-XXX          BRAVO MS-L P/60
    501651-XXX          BRAVO MS-L P/90
    501659-XXX          BRAVO MS-T P/60
    501660-XXX          BRAVO MS-T P/90
    501679-XXX          BRAVO MS P-60
    501680-XXX          BRAVO MS P-90
    510695-XXX          ADVANTAGE! 6075P
    501696-XXX          ADVANTAGE! 8075P
    501697-XXX          ADVANTAGE! 8090P
    501699-XXX          PREMMIA MX P/75
    501701-XXX          BRAVO MS P-75
    501702-XXX          BRAVO MS-L P/75
    501703-XXX          BRAVO MS-T P/75
    501754-XXX          BRAVO MS P/100
    501765-XXX          BRAVO MS P-75
    501710-XXX          BRAVO LC P/75
    501713-XXX          ADVANTAGE! 6060P

    SOLUTION

    The RSTDRV capacitor has been removed from the new version of the riser card.
    The solution is to replace the riser card.  See part numbers and revision
    levels below.

    CAUTION

    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.

    PREREQUISITES

    A full backup of all data on the hard drive in the computer is strongly
    suggested.

    TIME REQUIRED

    30 minutes.

    STATUS VERIFICATION

    The revision level of the AST riser card can be identified by observing the
    revision letter at the end of the nine-digit part number located on the solder
    side of the card.

    PARTS REQUIRED
    AST PART NUMBER               DESCRIPTION                        REVISION

    202719-001              PCBA RISER CARD LOW PROFILE                 B
    202720-001              PCBA RISER CARD MID SIZE               X04 or higher
    202721-001              *PCBA RISER CARD FULL SIZE             X02 or higher
    202721-002              PCBA RISER CARD FULL SIZE              X02 or higher
    202722-001              PCBA RISER CARD MINI TOWER             X04 or higher

    *502141405HH (HK) 502091718MH (FW)

    TOOLS REQUIRED

    Standard computer tools.

    INSTALLATION PROCEDURE

    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.

    Remove the riser card according to procedures approved and prescribed by
    AST Research, Inc.

    CHECK-OUT PROCEDURE

    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.

    NOTE

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

    The warranty on this system will become VOID if this change is completed
    by ANYONE other than an AST Authorized Service Center.