v Check the power supplies, see Power-supply LEDs.
v Follow the suggested actions in the order in which they are listed in the Action column until the problem
is solved.
v See Chapter 3, “Parts listing, Type 8864,” on page 23 to determine which components are customer
replaceable units (CRU) and which components are field replaceable units (FRU).
v If an action step is preceded by “(Trained service technician only)”, that step must be performed only by a
trained service technician.
Lit light path
diagnostics LED with
the system-error or
system-information
LED also lit Description Action
FAN A fan has failed or has been
removed.
Note: A failing fan can also cause
the TEMP LED to be lit.
1. Reinstall the removed fan.
2. If an individual fan LED is lit, replace the fan.
3. Reseat the microprocessor tray.
4. (Trained service technician only) Replace the
microprocessor tray.
PCI BRD The PCI board has failed.
1. (Trained service technician only) Reseat the PCI
board assembly.
2. (Trained service technician only) Replace the PCI
board assembly.
CPU BRD The microprocessor tray has failed.
1. Reseat the microprocessor tray.
2. (Trained service technician only) Replace the
microprocessor tray.
I/O BRD The I/O board has failed.
1. Reseat the I/O board.
2. Replace the I/O board.
Remind button
You can use the remind button to put the system-error LED on the operator
information panel into Remind mode. When you press the remind button, you
acknowledge the error but indicate that you will not take immediate action. The
system-error LED flashes while it is in Remind mode.
The system-error LED stays in Remind mode until one of the following conditions
occurs:
v All known errors are corrected.
v The server is restarted.
v A new error occurs (the LED is lit again).
Power-supply LEDs
The following table describes the power-supply LEDs and suggested actions to
correct the detected problems.
The following minimum configuration is required for the power-supply dc good LED
to be lit:
v Power supply
v Power backplane
v Power cord
v Microprocessor tray
108 IBM System x3850 Type 8864: Problem Determination and Service Guide