IBM 6H0, Service Manual

Page: 186 / 561

Performing Slow Boot
On this system, the error code displayed in the operator panel may not indicate the root
cause of the problem. To fully analyze all of the available information, perform the
following steps before doing a hardware repair or replacement:
1. Record the 8-character error code (and location code if present) in the primary I/O
drawer operator panel.
2. Do a slow-mode boot to the SMS menus. This boot can be specified using the
System Power Control Menu on the service processor main menu. (A fast-mode
boot skips much of the built-in diagnostic testing.) A slow-mode boot may yield a
new 8-character error code on the primary I/O drawer operator panel and new
errors in the service processor error log. If a new error code is reported, use it in
subsequent steps to continue problem analysis. If the system hangs with the same
error code, continue with the next step in the Checkpoints and Error Codes Index. If
no 8-character error code is displayed in the op panel, use the original error code
and continue with the next step in the Checkpoints and Error Codes Index.
3. A slow boot in service mode should result in the
″
Diagnostic Operating Instructions
″
panel being displayed.
4. Press enter to continue to the
″
Function Selection
″
menu
5. Enter option 5,
″
Single User Mode
″
.
6. When prompted, enter the root password.
7. At the prompt, issue the
shutdown -F
command.
8. At this point, the service processor menus should be available to examine the
service processor error log.
Confirming Initial Error Code
The service processor may have recorded one or more symptoms in its error log. If the
system has attempted to boot since an error terminated normal operation, there may be
specific fault information in the service processor error log. Examine this error log
before proceeding (see “System Information Menu” on page 382).
In the service processor error log, the most recent error is at the top of the list and the
oldest error is at the bottom. It is also important to look at the time stamp associated
with each error. (The time stamps in the service processor error log reflect coordinated
universal time (UTC), which is also referred to as Greenwich mean time.)
On this system, the error code displayed in the primary drawer op panel may not be
indicative of the root cause of the problem. Find the error code in the service processor
error log that directed you to this note. (If the error code is not in the error log, perform
the service actions for the error code that was first reported.) Observing the
timestamps, look for a group of failures that happened within minutes prior to this error
code. In this group, start at the error code with the earliest timestamp. To get a list of
possible FRUs, select the detail screen for each arror code and perform the listed repair
actions. If the repair actions for an error code are ineffective, continue to work upward
through this group of errors codes (which is forward in time from the earliest timestamp
to the latest) until the problem is fixed, or you reach the error code that was first
reported. If the system is still not fixed, go to “MAP 1540: Minimum Configuration” on
page 113.
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Service Guide