Lenovo ThinkCentre M70t Hardware Maintenance Manual page 45

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
"System board" on page 99.
.
Chapter 4 Service checkout and symptom-to-FRU index
39