Tr oubleshootingDiagnostic LightsCAUTION: Before you begin any of the procedures in this section, follow the safety instructions thatshipped with your computer.Your computer has three keyboard status lights located above the keyboard. During normaloperation, the keyboard status lights display the current status (on or off) of the Num Lock, CapsLock, and Scroll Lock features. If the computer starts without error, the lights flash, and then turnoff. If the computer malfunctions, however, you can use the status of the lights to help identify theproblem.NOTE: After the computer completes POST, the Num Lock light may remain on, depending on your BIOSsettings. For more information on using the system setup program, see "System Setup Program" on page 93.Diagnostic Light Codes During POSTTo troubleshoot a problem with your computer, read the sequence of the keyboard status lights inorder from left to right (Num Lock, Caps Lock, and then Scroll Lock). If the computer malfunctionsthe individual lights display a status of either On , Off , or Flashing .Light Pattern Problem Description Suggested ResolutionNo memory modulesare detected.• If two or more memory modules areinstalled, remove the modules, thenreinstall one module and restart thecomputer. If the computer startsnormally, continue to installadditional memory modules (one at atime) until you have identified afaulty module or reinstalled allmodules without error (see "Memory"on page 115).• If available, install working memory ofthe same type into your computer (see"Memory" on page 115).• If the problem persists, contact DellSupport.Tr oubleshooting 71
