Introduction To Diagnostics - IBM 6150 Hardware Maintenance Manual

TNL SN20-9843 (03-27-87) to 75X0152 or 75X0166
Introduction to Diagnostics
2-4 Service Manual
Note: Some system unit components do not cool properly and may fail
intermittently when covers are off. For this reason do not power the system
unit on longer than 10 minutes with the covers off.
The diagnostic programs are divided into six types:
• The
Resident Power-On Self-Test
(POST) programs are in
Read-Only
Memory
(ROM) modules on the processor board. These programs run
when the system unit is first powered on.
The Resident POST programs check the system unit components needed
to load programs from the fixed disk or diskette. See page 2-6 for more
information about the Resident POST programs.
• The
Loadable POST
programs load from the fixed disk or the diagnostic
diskettes. These programs run when the Resident POST programs
complete.
The Loadable POST programs first sense the adapters and options
installed in the system unit and build an
Installed Features List.
Before
any checkout routines are run, the installed features list is compared to
the
Configuration Record
on the fixed disk. See page 2-6 for more
information about the Loadable POST programs.
Pressing the Ctrl-Alt-Pause keys cause the Loadable POST programs to
run.
• The
Diagnostic Routines
are on the diagnostic diskettes. The
Problem
Determination Guide directs the system user to run the Diagnostic
Routines to check the system unit during problem determination. See
page 2-11 for more information about the Diagnostic Routines.