IBM THINKPAD S05L-1270-01 - Manual (Page 154)

Diagnostic Error Codes
If an error is detected, the following appears:
Large X on the left side of the device icon.
Device ID (three digit)
FRU code (four digit)
Error code (two digit)
The device ID and error code indicate the detailed portion
of the FRU that caused the error. If replacing a FRU does
not correct the problem, see the device ID or error code
from the previous failure. If they have changed, the cause
might be because the new FRU is detective or that the
FRU was incorrectly installed.
Device ID: If an error is detected by the diagnostic
tests, a three-digit device ID is displayed, indicating the
suspected device.
Icon Device
ID Suspected Device
001 System board
003 Keyboard
007 Math coprocessor
086 Pointing device
002 Memory
050 Display
017 Hard disk drive
142 IBM Mobile Systems HMM