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AST RESEARCH, INC.         TECHNICAL BULLETIN # 1154                4-24-95

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				INTERPRETATION OF MANHATTAN SMP LEDS


This is an informational bulletin.  

The supplemental information included in this bulletin is intended to assist 
technicians supporting the AST Manhattan SMP. 

The Manhattan SMP includes a number of hardware-based diagnostic tools, 
including the LEDs on each of the IOSM, Processor and Memory boards in the 
system.  These LEDs provide information about the status of the board, and if 
a failure occurred, may give basic failure information as well.  
The information below will help interpret the meanings of the LEDs.

INTERPRETATION

There are three types of LEDs on the Manhattan SMP's system bus boards 
(IOSM, Processor and Memory).  The LEDs may be lit as red, green, or 
yellow.

RED LEDS

Red LEDs indicate an error condition.  The error may be either a fatal or a 
non-fatal error.

The red LEDs will indicate one of the following:

1. The failure of a system bus board: IOSM, Processor, or Memory, indicated 
by patterns of LEDs on the board.  See AST Manhattan SMP Installation and 
Maintenance Manual (001169-001, Table 7-4 or 001725-001. Table 13-4) for a 
description of each LED combination.

2. The failure of an EISA bus adapter.  The individual board is not identified.

3. The failure of a software driver that is bad or has been incorrectly 
configured.  This condition may result, for example, in the system attempting 
to access memory addresses when no physical memory is installed at the 
addressed location.

If the error was non-fatal, the system does not crash.  The error will be 
reported via one of the Manhattan SMP's Operating System utilities: MP31.NLM 
for NetWare or EFS for SCO UNIX.  Only one occurrence of an error is reported 
every 30 minutes.  If multiple errors are reported consistently, the cause of 
the problem should be investigated and corrected.  Use standard hardware and 
software troubleshooting techniques to isolate the hardware or software 
component responsible for the error.

YELLOW LEDS

Yellow LEDs indicate that a single bit memory error occurred and has been 
corrected.
 
The yellow LEDs will indicate a single occurrence of a single bit memory error 
on each memory board.

The memory board corrects the single bit memory errors, and the error is 
reported via one of the Manhattan SMP's Operating System utilities: 
MP31.NLM for NetWare or EFS for SCO UNIX.  The utility will indicate on 
which memory board the single bit memory error occurred.  Only one 
occurrence of an error is reported every 30 minutes. If multiple errors are 
reported consistently, the cause of the problem should be investigated and 
corrected. Exercise the indicated memory board by running Advanced System 
Diagnostics, which will isolate the SIMM bank that needs to be replaced.

GREEN LEDS

Green LEDs indicate that the board is in the Ready/Idle state.  The LEDs also 
indicate:

1. An active/enabled board.  The LED will be on, flashing, or very dim when 
   the board is active.

2. An idle board.  The LED stays ON solid and does not flash.  This condition 
   indicates that the board passed POST testing, and was enabled, but is not 
   currently in use by the system.

3. A disabled board.  The LED is OFF.  This condition indicates that the board 
   failed POST testing and was disabled.  A disabled board will not be tested 
   or detected by Advanced System Diagnostics.

TROUBLESHOOTING TECHNIQUE

If a system crashes, do not turn the system power OFF.  Open the side door and 
identify the status of the LEDs.  Check to see which LEDs are ON or OFF, and 
check the color of each LED.

If red LEDs are ON, see the Manhattan SMP Installation and Maintenance 
Manual for more information and take any required corrective action.

If any green LEDs are OFF, the board was disabled before the system crashed 
or the board was active when the system crashed.  In either case, replace any 
board on which the green LED is OFF.