IBM ThinkPad R40 Hardware Maintenance Manual page 73

Removing and replacing a FRU
W hen in s ta llin g : With the notched end of the DIMM
toward the socket, insert the DIMM into
the socket, and then press it firmly. Pivot
the DIMM until it snaps into place. Make
sure that the card is firm ly fixed in the
slot and does not move easily.
ThinkPad R40 69