Apple Xserve Intel (Late 2006) DIY Procedure for Power Distribution Board - Manual (Page 9)

Xserve (Late 2006) Power Distribution Board Replacement Instructions 
Power Distribution Board
Locate the power distribution board.
Release the thumbscrew that secures the power distribution board to the enclosure.
Note: The thumbscrew is captive; you cannot remove it.
Pull the board toward the side of the enclosure in the direction shown, to disconnect it from
its connector on the logic board.
Lift up the board and remove it from the enclosure.
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