Lenovo TS100 - Manual (Page 142)

System board
mounting screws
(8 places)
Fan-sink mounting
bracket slots
10. Slide the system board toward the front of the server to disengage the tabs on
the fan sink mounting bracket from the slots on the bottom of the chassis;
then, carefully lift the system board out of the server.
11. Remove the four screws that secure the fan sink retention module 1 and fan
sink mounting bracket 2 to the system board; then, set the fan sink retention
module, fan sink mounting bracket, and screws aside for use later.
Note: Make sure that you observe the orientation of the fan sink retention
module before you move it so that when you reinstall it, you install it in the
same orientation.
124 ThinkServer TS100 Types 6431, 6432, 6433, and 6434: Hardware Maintenance Manual