Dell Precision 490 Desktop Quick Reference Guide - Page 41

Light Pattern Problem Description A possible USB failure has occurred. No memory modules are detected. No memory modules are detected. System board failure has occurred. Suggested Resolution Reinstall all USB devices, check cable connections, and then restart the computer. 1 Reseat the memory modules to ensure that your computer is successfully communicating with the memory. 2 Restart the computer. 3 If the problem still exists, remove all the memory modules and install one memory module in memory module connector DIMM_1. 4 Restart the computer. A message appears stating that because your memory is not paired, the system will operate with reduced performance and reduced error-correction capability 5 Press to boot to the operating system. 6 Run the Dell Diagnostics. See your User's Guide for more information. 7 If the memory module passes, shut down the computer, remove the memory module, and then repeat the process with the remaining memory modules until a memory error occurs during start-up or diagnostic testing. If the first memory module tested is defective, repeat the process with the remaining modules to ensure that the remaining modules are not defective. 8 When the defective memory module is identified, contact Dell for a replacement. • If you have one memory module installed, reinstall it and restart the computer. • If you have two or more memory modules installed, remove the modules, reinstall one module, and then restart the computer). If the computer starts normally, reinstall an additional module. Continue until you have identified a faulty module or reinstalled all modules without error. • If available, install properly working memory of the same type into your computer. • If the problem persists, contact Dell. Contact Dell for technical assistance. Quick Reference Guide 41