Lenovo ThinkCentre M80s Gen 3 Maintenance Manual page 47

e. External Cache
f. External Cache RAM
g. Hard disk drive
h. Diskette drive
3. Turn on the computer to retest the system.
4. Repeat steps 1 through 3 until you find the failing device or adapter.
If all devices and adapters have been removed, and the problem continues, replace the system board. See
Chapter 6 "Hardware removal and installation" on page 47.
.
Chapter 4 Service checkout and symptom-to-FRU index
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