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AST RESEARCH, INC.          TECHNICAL BULLETIN # 1203                6-6-95
			 
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EXPANSION CHASSIS VOLTAGE FAIL INDICATIONS


PROBLEM

An incorrect integrated circuit may cause spurious voltage fail indications in 
the expansion chassis.


CAUSE

An integrated circuit did not meet specifications.


SYSTEMS AFFECTED
AST PART NUMBER AND DESCRIPTION

501516-XXX     HW MOD MANHATTAN EXPANSION CABINET


SOLUTION

Replace the sensor board (part number 202644-002) with revision 04 or higher.


CAUTION

This modification should be performed 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 sensor 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

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.  


NOTE

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