Replacing The Speaker System - Lenovo B40–30 Hardware Maintenance Manual

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 system fan
Step 1. 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.
Step 2. Unplug all power cords from electrical outlets.
Step 3. 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.
Step 4. Remove the stand base. Refer to "Removing the stand base".
Step 5. Remove the foot cover. Refer to "Removing the foot cover".
Step 6. Remove the stand holder. Refer to "Removing the stand holder".
Step 7. Remove the middle cover. Refer to "Removing the middle cover".
Step 8. Remove the EMI cover. Refer to "Removing the EMI cover".
Step 9. Remove the sealing tape between the system fan and heat-sink.
Step 10. Remove the three screws that secure the system fan to the chassis.
Step 11. Disconnect the power cable from the motherboard.
Step 12. Lift up the system fan to remove it.
Step 13. To install the new system fan:
a. Place the new system fan into position, and then secure it to the chassis with three screws.
b. Connect the system fan power cable to the connector on the motherboard.
c. Use the sealing tape to seal the gap in-between the system fan and heat-sink.
Step 14. Reattach the EMI cover, middle cover, stand holder, foot cover and stand base.

Replacing the speaker system

Note: Turn off the computer and wait 3 to 5 minutes to let it cool down before removing the cover.
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Lenovo B40–30 All-In-One Computer Hardware Maintenance Manual