Allied Telesis AT-SBx31CFC960 - Manual (Page 276)

Chapter 13: Replacing Modules
276
Figure 175. Installing a New AT-SBxFAN06 Fan Module
2. When you feel the fan module make contact with the connector on the
backplane, gently push on the top and bottom of the faceplate to seat
the module on the connector. Refer to Figure 176 on page 277.