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

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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.