Lenovo ThinkPad T420 4236 User Manual page 156

Prerequisites for the procedure
DANGER
During electrical storms, do not connect the cable to or disconnect it from the telephone outlet
on the wall.
DANGER
Electric current from power, telephone, and communication cables is hazardous. To avoid shock
hazard, disconnect the cables before opening the cover of this slot.
Attention: Before you start installing a PCI Express Mini Card, touch a metal table or a grounded metal
object. This action reduces any static electricity from your body. The static electricity could damage the card.
Replacement instructions
To replace the PCI Express Mini Card, do as follows:
1. Turn off the computer; then disconnect the ac power adapter and all cables from the computer. Wait for
a few minutes, till the inside of the computer cools, before you start the following procedures.
2. Close the computer display, and turn the computer over.
3. Remove the battery. For more information about how to remove the battery, refer to "Replacing the
battery" on page 111.
4. Loosen the screw on the memory slot cover (1), then remove the cover (2).
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User Guide