Troubleshooting Tools 47Troubleshooting ToolsDiagnostic LightsCAUTION: Before you begin any of the procedures in this section, follow the safety instructions in theProduct Information Guide.To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" onthe front panel (see "Back View of the Computer" on page 63). When the computer starts normally,the lights flash. After the computer starts, all four lights display solid green. If the computermalfunctions, the color and sequence of the lights identify the problem.Light Pattern Problem Description Suggested ResolutionThe computer is in a normal "off"condition or a possible pre-BIOSfailure has occurred.The diagnostic lights are not litafter the computer successfullyboots to the operating system.Plug the computer into a working electricaloutlet and press the power button. Also see"Power Problems" on page 40.A possible processor failure hasoccurred.Contact Dell (see "Contacting Dell" onpage 122).Memory modules are detected,but a memory failure hasoccurred.• If you have two or more memory modulesinstalled, remove the modules, reinstallone module (see "Installing Memory" onpage 70), and then restart the computer. Ifthe computer starts normally, reinstall anadditional module. Continue until youhave identified a faulty module orreinstalled all modules without error.• If available, install properly workingmemory of the same type into yourcomputer (see "Installing Memory" onpage 70).• If the problem persists, contact Dell (see"Contacting Dell" on page 122).
