Positioner and server

A server comprising:

• a connector;
• and
• a positioner configured for positioning an expansion card to the connector, the positioner comprising:
• a base;
• a first moving piece movable relative to the base in a first direction between a reset position, a retreat position, and a buckled position;
• a first spring located in the base and configured to push the first moving piece towards the reset position;
• a second moving piece movable relative to the base in a second direction between a lower position and an upper position, the second direction substantially perpendicular to the first direction;
• and
• a second spring located in the base and configured to push the second moving piece towards the upper position,
• wherein when the first moving piece is at the reset position, the first moving piece pushes the expansion card to the connector;
• when the second moving piece is at the lower position and the first moving piece is at the reset position, the second moving piece and the first moving piece cooperatively clamp the expansion card in the second direction;
• when the first moving piece is at the retreat position or at the buckled position, the first moving piece is detached from the expansion card;
• when the first moving piece is at the buckled position and buckled by the second moving piece at the lower position, the second moving piece is pressed by the expansion card and the second moving piece moves from the upper position to the lower position.