Lenovo A540 All In One - Manual (Page 35)

Step 7. Remove the heat-sink by lifting it up.
Attention: Place the heat-sink upside down on a flat surface to prevent thermal grease from contaminating
other components.
Attention: Use an alcohol pad to wipe the thermal grease off the heat-sink and CPU.
Step 8. 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 9. Line up the new heat-sink then secure it to the motherboard with the 8 screws.
Step 10. Attach the system fan to the new heat-sink and secure it with the screws.
Step 11. Reattach the base cover and secure it with the screws.
Replacing the speaker system
Note: Turn off the computer and wait 3 to 5 minutes to let it cool down before removing the cover.
To replace the speaker system:
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. Disconnect the speaker cable from the connectors on the motherboard.
Chapter 7 . Replacing hardware 29