Troubleshooting Tools 45Troubleshooting ToolsDiagnostic LightsCAUTION: Before you begin any of the procedures in this section, follow the safety instructionslocated in the Product Information Guide.To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" onthe front panel (see page 57). When the computer starts normally, the lights flash. If the computermalfunctions, the color and sequence of the lights identify the problem. After the computercompletes POST, all four lights turn off before booting to the operating system.Light Pattern Problem Description Suggested ResolutionThe computer is in a normal "off"condition or a possible pre-BIOS failurehas occurred.Plug the computer into a workingelectrical outlet and press the powerbutton.A possible processor failure has occurred. Contact Dell (see page 111).Memory modules are detected, but amemory failure has occurred.• If you have two or more memorymodules installed, remove themodules, reinstall one module (seepage 66), and then restart thecomputer. If the computer startsnormally, reinstall an additionalmodule. Continue until you haveidentified a faulty module orreinstalled all modules without error.• If available, install properly workingmemory of the same type into yourcomputer (see page 65).• If the problem persists, contact Dell(see page 111).
