Lenovo x3550 M4 Installation And Service Manual page 153

Table 14. Light path diagnostics panel LEDs (continued)
v Follow the suggested actions in the order in which they are listed in the Action column until the problem is
solved.
v If an action step is preceded by "(trained technician only)," that step must be performed only by a trained
technician.
LED Description
CPU When only the CPU LED is lit, a
microprocessor has failed.
CPU + CONFIG
When both the CPU LED and the
CONFIG LED are lit, the
microprocessor configuration is
invalid.
Action
If the CONFIG LED is not lit, a microprocessor failure occurs,
complete the following steps:
1. (Trained technician only) Make sure that the failing
microprocessor and its heat sink, which are indicated by a
lit LED on the system board, are installed correctly. See
"Replacing a microprocessor and heat sink" on page 304
for information about installation and requirements.
2. (Trained technician only) Replace the failing
microprocessor (see "Removing a microprocessor and heat
sink" on page 299 and "Replacing a microprocessor and
heat sink" on page 304).
3. For more information, go to http://www.ibm.com/
support/entry/portal/docdisplay?lndocid=SERV-CALL.
If the CONFIG LED and the CPU LED are lit, the system
issues an invalid microprocessor configuration error.
Complete the following steps to correct the problem:
1. Check the microprocessors that were just installed to
make sure that they are compatible with each other (see
"Replacing a microprocessor and heat sink" on page 304
for additional information about microprocessor
requirements).
2. (Trained technician only) Replace the incompatible
microprocessor.
3. Check the system-error logs for information about the
error. Replace any component that is identified in the
error log.
Chapter 4. Troubleshooting
135