Lenovo A540 All In One - Manual (Page 36)

Step 6. Remove the 4 screws that secure the speaker system to the motherboard.
Step 7. Detach the speaker from the chassis.
Step 8. To install the new speaker system:
a. Attach the new speaker cable to the chassis and secure it with the 4 screws.
b. Connect the new speaker cable to the motherboard.
Step 9. Reattach the base cover and secure it with the screws.
Replacing the motherboard
Note: Turn off the computer and wait 3 to 5 minutes to let it cool down before removing the cover.
To replace the motherboard:
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 base cover. Refer to “Removing the base cover”.
Step 5. Remove a memory module. Refer to “Replacing a memory module”.
Step 6. Remove the system fan. Refer to “Replacing the system fan”.
Step 7. Remove the heat-sink. Refer to “Replacing the heat-sink”.
Step 8. Remove all the cables connected to the motherboard.
30 Lenovo A540/A740Hardware Maintenance Manual