Lenovo ThinkPad T420 User Manual page 143

6. With the notched end of the SO-DIMM toward the contact edge side of the socket, insert the SO-DIMM
into the socket at an angle of about 20 degrees (1); then press it in firmly (2).
7. Pivot the SO-DIMM downward until it snaps into place.
8. Make sure that the SO-DIMM is firmly fixed in the slot and cannot be moved easily.
9. Put the memory slot cover back in place (1), close the cover (2), and then tighten the screw (3).
10. Put the battery back in place, turn the computer over again, and reconnect the cables. For more
information about how to reinstall the battery, refer to "Replacing the battery" on page 111.
Replacing memory in the slot under the keyboard
1. Turn off the computer; then disconnect the ac power adapter and all cables from the computer.
2. Close the computer display, and turn it over.
3. Remove the battery. For more information, refer to "Replacing the battery" on page 111.
.
Chapter 6 Replacing devices
125