Microprocessor Problems - IBM x3950 Problem Determination And Service Manual

Microprocessor problems

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 8878 and 8879," on page 109 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.
Symptom
The server emits a continuous
beep during POST, indicating
that the startup (boot)
microprocessor is not working
correctly.
Action
1. Correct any errors indicated by the light path (see "Light path diagnostics" on
page 50).
2. Make sure that all microprocessors are supported on this server, and that they
all match in speed and cache size.
3. (Trained service technician only) Make sure that the microprocessor 1 is seated
correctly.
4. Reseat the following components:
a. (Trained service technician only) Microprocessor 1
b. Microprocessor VRM 3 or 4
c. Microprocessor tray
5. (Trained service technicians only) If there is no indication of which
microprocessor has failed, isolate the error by testing with one microprocessor
at a time.
6. Replace the following components one at a time, in the order shown, restarting
the server each time.
a. (Trained service technician only) Microprocessor 1
b. Microprocessor VRM 3 or 4
c. (Trained service technician only) Microprocessor tray
7. (Trained service technician only) If there are multiple error codes or light path
diagnostics LEDs that indicate a microprocessor error, reverse the locations of
two microprocessors to determine whether the error is associated with a
microprocessor or with a microprocessor socket. If the error codes or LEDs
indicate an error that is associated with microprocessor socket 3 or 4, reverse
the locations of VRM 3 and VRM 4.
v If the error is associated with a microprocessor, replace the microprocessor.
v If the error is associated with a VRM, replace the VRM.
v If the error is associated with a microprocessor socket, replace the
microprocessor tray.
43
Chapter 2. Diagnostics