WARNING: Disconnect all power sources before opening the computercover or panels. After you finish working inside the computer, replace allcovers, panels, and screws before connecting to the power source.CAUTION: To avoid damaging the computer, make sure that the worksurface is flat and clean.CAUTION: To avoid damaging the components and cards, handle them bytheir edges and avoid touching pins and contacts.CAUTION: You should only perform troubleshooting and repairs asauthorized or directed by the Dell technical assistance team. Damage due toservicing that is not authorized by Dell is not covered by your warranty. Seethe safety instructions that shipped with the product or at dell.com/regulatory_compliance.CAUTION: Before touching anything inside your computer, ground yourselfby touching an unpainted metal surface, such as the metal at the back ofthe computer. While you work, periodically touch an unpainted metalsurface to dissipate static electricity, which could harm internalcomponents.CAUTION: When you disconnect a cable, pull on its connector or on its pull-tab, not on the cable itself. Some cables have connectors with locking tabsor thumb-screws that you must disengage before disconnecting the cable.When disconnecting cables, keep them evenly aligned to avoid bending anyconnector pins. When connecting cables, make sure that the ports andconnectors are correctly oriented and aligned.CAUTION: To disconnect a network cable, first unplug the cable from yourcomputer and then unplug the cable from the network device.CAUTION: Press and eject any installed card from the media-card reader.Recommended toolsThe procedures in this document may require the following tools:• Philips screwdriver• Plastic scribe11