Dell Inspiron 531S Owner's  Manual - Page 126

Drive Interface Connectors The drive cable connectors are keyed for correct insertion. Properly align the cable connector key on the cable and the drive before connecting. Serial ATA Connector 1 2 1 interface cable 2 interface connector Connecting and Disconnecting Drive Cables When connecting and disconnecting a serial ATA data cable, disconnect the cable using the pull-tab. The serial ATA interface connectors are keyed for correct insertion; that is, a notch or a missing pin on one connector matches a tab or a filled-in hole on the other connector. Hard Drives CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide. CAUTION: To guard against electrical shock, laceration by moving fan blades, or other unexpected injuries, always unplug your computer from the electrical outlet before opening the cover. NOTICE: To avoid damage to the drive, do not set it on a hard surface. Instead, set the drive on a surface, such as a foam pad, that will sufficiently cushion it. NOTICE: If you are replacing a hard drive that contains data you want to keep, back up your files before you begin this procedure. Check the documentation for the drive to verify that it is configured for your computer. 126 Removing and Installing Parts