Understanding DECsystem 5100 Self Test Failure

Robert Jarratt robert.jarratt at ntlworld.com
Sun Jan 4 13:46:39 CST 2015

When I power up my DECsystem 5100 I get the output shown at the end of this
email. I thought this was to do with the DS1287 chip as it seems be an NVRAM
battery error (perhaps). Since I know these devices fail I took out the
DS1287, put in a socket and then bought a replacement DS12887A. But I still
get the same problem. It could be that I bought a bad replacement, or that I
have done some damage in my desoldering of the original, or it could be that
the error is something completely different. In fact the Maintenance Manual
suggests test 9 is to do with the DZ, and I can't find what test 4 relates


Does anyone know what this failure is if it isnt' the DS1287?


Is there an easy way to test a DS1287?







13..12..11..10..09..?45a nv ba?45a nv bat

                                         ?45a nv ba?45a nv bat

                                                              ?45a nv ba?45a
nv bat

08..07..06..05..04..?45a nv bat


?45a nv bat

           ?45a nv bat

                      ?45a nv bat

                                 ?45a nv bat

                                            ?45a nv bat

                                                       ?45a nv bat



KN230 V1.4



>> conf -f

hardware: revision 1

firmware: revision 5

cpu: revision 2.32

fpu: revision 3.32

security switch: secure mode

password: clear

eeprom: valid

ethernet hardware address: 08-00-2b-27-04-50

option board: not present

memory: total size   8MBs

     bank0   4MB SIMMs  size:  8MBs       0 bad pages

scsi peripherals

  unit type           product            removable/fixed    capacity

    7  host adapter

>> prcache




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