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 electrical outlet.CAUTION: To avoid damaging the computer, ensure that the work surface isflat 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 www.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 metal surfaceto dissipate static electricity, which could harm internal components.CAUTION: When you disconnect a cable, pull on its connector or on its pulltab, 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, ensure that the ports andconnectors are correctly oriented and aligned.CAUTION: Press and eject any installed card from the media-card reader.Recommended toolsThe procedures in this document may require the following tools:• Phillips screwdriver #1• Plastic scribe11