Important: To avoid damaging the microprocessor contacts, keep the microprocessor completely level
while installing it into the socket.
Step 15. Lower the microprocessor straight down into its socket on the motherboard.
Step 16. To secure the microprocessor in the socket, close the microprocessor retainer and lock it into
position with the small handle.
Step 17. Use a thermal grease syringe to place 5 drops of grease on the top of the microprocessor. Each
drop of grease should be 0.03ml (3 tick marks on the grease syringe).
Step 18. Reattach the heat-sink, system fan, EMI cover, middle cover, optical drive, computer stand and
the rear cover.
Replacing the rear I/O module
Note: Turn off the computer and wait 3 to 5 minutes to let it cool down before removing the cover.
Note: It may be helpful to place the computer face-down on a soft flat surface for this procedure. Lenovo
recommends that you use a blanket, towel, or other soft cloth to protect the computer screen from scratches
or other damage.
To replace the rear I/O module:
Remove any media (disks, CDs, DVDs or memory cards) from the drives, shut down the operating
system, and turn off the computer and all attached devices.
Unplug all power cords from electrical outlets.
Disconnect all cables attached to the computer. This includes power cords, input/output (I/O)
cables, and any other cables that are connected to the computer. Refer to "Left and right view"
and "Rear view" for help with locating the various connectors.
Remove the rear cover. Refer to "Removing the rear cover".
Remove the computer stand. Refer to "Removing the computer stand".
Remove the optical drive. Refer to "Replacing the optical drive".
Remove the middle cover. Refer to "Removing the middle cover".
Remove the EMI cover. Refer to "Removing the EMI cover".
Remove the 3 screws that secure the rear I/O module and metal bracket to the chassis.
IdeaCentre B340Hardware Maintenance Manual