Intermittent Problems; Memory Problems; Monitor Problems - IBM xSeries 455 Installation Manual

Intermittent problems

Symptom
A problem occurs only
occasionally and is difficult to
diagnose.

Memory problems

Symptom
The amount of system memory
displayed is less than the
amount of physical memory
installed.

Monitor problems

Some IBM monitors have their own self-tests. If you suspect a problem with your
monitor, see the information that comes with the monitor for instructions for testing
and adjusting the monitor. If you cannot diagnose the problem, call for service.
Symptom
The screen is blank.
Only the cursor appears.
Suggested action
Verify that:
v All cables and cords are connected securely to the rear of the server and
attached options.
v When the server is turned on, air is flowing from the rear of the server at the fan
grille. If there is no airflow, the fan is not working. This causes the server to
overheat and shut down.
v The SCSI bus and devices are configured correctly and the last external device
in each SCSI chain is terminated correctly.
Check the system-error LED on the front of the server. See "Light path diagnostics"
on page 56 for more information.
If the problem remains, call for service.
Suggested action
Verify that:
v The memory modules are seated properly.
v You have installed the correct type of memory.
v All banks of memory are enabled. The server might have automatically disabled
a DIMM bank when it detected a problem.
v Memory mirroring is disabled.
If the problem remains, call for service.
Suggested action
Make sure that:
v The server power cord is connected to the server and a working electrical outlet.
v The monitor cables are connected correctly.
v The monitor is turned on and the brightness and contrast controls are adjusted
correctly.
Note: During startup, the server might appear to be unresponsive for an unusual
length of time (30 seconds to several minutes). In a single-node configuration, the
locator LED on the front of the server flashes during startup and indicates that
POST is in progress. In a multi-node configuration during startup, the locator LED
flashes on the primary node and is lit on the secondary nodes.
If the problem remains, call for service.
Call for service.
Chapter 5. Solving problems
53