Troubleshooting Your System 153Troubleshooting System MemoryCAUTION: Many repairs may only be done by a certified service technician. Youshould only perform troubleshooting and simple repairs as authorized in yourproduct documentation, or as directed by the online or telephone service andsupport team. Damage due to servicing that is not authorized by Dell is not coveredby your warranty. Read and follow the safety instructions that came with theproduct.NOTE: Invalid memory configurations can cause your system to halt at startupwithout video output. See "General Memory Module Installation Guidelines" onpage 106 and verify that your memory configuration complies with all applicableguidelines.1 If the system is operational, run the appropriate online diagnostic test.See "Running the System Diagnostics" on page 161.If diagnostics indicates a fault, follow the corrective actions provided bythe diagnostic program.2 If the system is not operational, turn off the system and attachedperipherals, and unplug the system from the power source. Wait at least 10seconds and then reconnect the system to power.3 Turn on the system and attached peripherals and note the messages on thescreen.Go to step 12 if an error message appears indicating a fault with a specificmemory module.4 Enter the System Setup program and check the system memory setting.See "Memory Settings Screen" on page 57. Make any changes to thememory settings, if needed.If the memory settings match the installed memory but a problem is stillindicated, go to step 12.5 Turn off the system and attached peripherals, and disconnect the systemfrom the electrical outlet.6 Open the system. See "Opening the System" on page 78.7 Check the memory channels and ensure that they are populated correctly.See "General Memory Module Installation Guidelines" on page 106.8 Reseat the memory modules in their sockets. See "Installing MemoryModules" on page 109.