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AST RESEARCH, INC.          TECHNICAL BULLETIN # 1193               5-24-95

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DESKTOP SYSTEMS HANG OPENING AND CLOSING APPLICATIONS IN WINDOWS


PROBLEM

Various desktop systems may hang when attempting to open or close applications 
in Windows.  The system may return error messages such as the following:

Excel causes a General Protection Fault in module VGA.DRV at 0009:0D26.

or

EMM 386 has detected error # 06 in an application at memory address 00B8:0BC9.


CAUSE

There is an impedance mismatch (using certain vendors' parts) in the memory 
address lines to the SIMMS.


SYSTEMS AFFECTED
AST PART NUMBER AND DESCRIPTION

501611-XXX          BRAVO MS 4-50S
501612-XXX          BRAVO MS 4-66D
501440-XXX          BRAVO MS 4-33S
501432-XXX          PREMMIA MX 4-100
501429-XXX          PREMMIA MX 4-66D
501655-XXX          BRAVO MS-L 4-50D
501644-XXX          ADVANTAGE! CMT 2-66D
501443-XXX          BRAVO MS-L 4-100T


SOLUTION

Return the system to an AST Authorized Service Center for system board 
replacement.  Replace the system board with the corresponding AST part 
number: 

AST PART NUMBER

202612-XXX
202637-XXX
202694-XXX
202695-XXX
202705-XXX

For specific revision levels, contact your AST Authorized Service Center.


NOTE

To find out if the system has the above problem, inspect the system board at 
locations U11, U12, and U13.  If the board has an IC (integrated circuit) part 
number 74F245 from Texas Instruments or Signetics, the board should be 
replaced.  See part numbers above.


CAUTION

This modification should be performed ONLY by a qualified service 
technician.  It is strongly recommended that this replacement 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 system board can be identified by observing 
the revision letter at the end of the nine-digit part number located on the 
solder side of the system board.


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 system board according to procedures approved and prescribed 
by AST Research, Inc.


CHECK-OUT PROCEDURE

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

NOTE

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

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