IBM 770 Hardware Manual
change. Replace only the FRU that changed the
symptoms.
symptoms.
Attention
A customized setup configuration (other than default
settings) may exist on the computer you are servicing.
Running Automatic Configuration may alter those
settings. Note the current configuration settings (using
the View Configuration option) and verify that the
settings are in place when service is complete.
settings) may exist on the computer you are servicing.
Running Automatic Configuration may alter those
settings. Note the current configuration settings (using
the View Configuration option) and verify that the
settings are in place when service is complete.
Hard Disk Drive Replacement Strategy:
Always try to run a low-level format before replacing a hard
disk drive.
disk drive.
Attention
The drive startup sequence in the computer you are
servicing might have been changed. Be extremely
careful during write operations such as copying,
saving, or formatting. Data or programs can be
overwritten if you select an incorrect drive.
servicing might have been changed. Be extremely
careful during write operations such as copying,
saving, or formatting. Data or programs can be
overwritten if you select an incorrect drive.
How to Use Error Messages:
Use the error
codes displayed on the screen to diagnose failures. If more
than one error code is displayed, begin the diagnosis with
the first error code. The cause of the first error code can
result in false error codes being displayed. If no error code
is displayed, see if the error symptom is listed in the
Symptom-to-FRU Index for the computer you are servicing.
than one error code is displayed, begin the diagnosis with
the first error code. The cause of the first error code can
result in false error codes being displayed. If no error code
is displayed, see if the error symptom is listed in the
Symptom-to-FRU Index for the computer you are servicing.
How to Read POST Error Messages:
POST
error messages are displayed on the screen as three, four,
five, or eight digits. The error messages that can be
displayed as shorter POST messages are highlighted in
this index. Some digits will represent different information
for SCSI errors versus non-SCSI errors.
five, or eight digits. The error messages that can be
displayed as shorter POST messages are highlighted in
this index. Some digits will represent different information
for SCSI errors versus non-SCSI errors.
The following example shows which digits display the
shorter POST error messages and also defines the SCSI
information in an eight-digit error message.
shorter POST error messages and also defines the SCSI
information in an eight-digit error message.
Shorter POST Messages
"""""""""""""""""""""
"
"
"
"
"
"
"""""""""""""""""""""""""""""""""""""""""
" ð " ð " ð " ð " ð " ð " ð " ð "
"""""""""""""""""""""""""""""""""""""""""
" ð " ð " ð " ð " ð " ð " ð " ð "
"""""""""""""""""""""""""""""""""""""""""
"
"
"
"
"
"
"
"
Reserved "
"
"
"
"
"
Size (SCSI)
"""""""""""
"
"
Slot Number (SCSI)
Device Code
"
Logical Unit Number (SCSI)
ID (SCSI)
All SCSI devices are set to a different SCSI ID. Duplicate
SCSI ID settings can generate a false error message. Use
the SCSI ID to determine whether the error message is
coming from an internal or an external device.
SCSI ID settings can generate a false error message. Use
the SCSI ID to determine whether the error message is
coming from an internal or an external device.
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