Apple Mac Pro (Mid 2010) - Manual (Page 77)

77 Chapter 3 Making a Good Thing Better
6 Align the card’s connector with the expansion slot and press the card into the slot.
Hook on card Retention bar PCI Express slot PCI slider
7 Press the card gently but firmly until the connector is fully inserted. Press only on the
bare areas of the card to avoid damaging the components. Don’t rock the card from
side to side or force it. If you meet resistance, check the connector and slot for damage
or obstructions, and then try inserting the card again.
8 Pull the card gently to make sure it’s properly connected. If it stays in place and its gold
connectors are barely visible, the card is connected.
9 Move the PCI slider to the right to secure the card.