IBM ThinkPad R40 Hardware Maintenance Manual page 146

Parts list
v Each FRU is available for all types or model, unless
specific types or models are specified.
v A CRU (Customer Replaceable Units) is identified by a
single asterisk (*) or two asterisks (**) in the CRU ID
column. An N in the CRU ID column means that the part
is not a CRU. A single asterisk (*) means that the part is
a Tier 1 CRU; two asterisks (**) mean that the part is a
Tier 2 CRU.
Tier 1 CRU:
(Example- Mouse, External Keyboard, and Hard-disk
drive with coin screw)
– NO TOOLS ARE REQUIRED.
– A coin or a thumb screw is acceptable.
– Minimal technical expertise is required.
– Minimal problem determination is required-less than
5 minutes.
Tier 2 CRU:
(Example- Adapter card, ThinkPad memory)
– Up to 4 screws or fasteners have to be removed.
– Some technical experience is required.
– HelpCenter assistance may be used.
– Problem determination can be done by customer,
either on site or with HelpCenter assistance.
(continued)
142
ThinkPad R40