Troubleshooting Your System 145Troubleshooting Your SystemSafety First—For You and Your SystemCAUTION: 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.Troubleshooting System Startup FailureIf your system halts during startup prior to video output, especially afterinstalling an operating system or reconfiguring your system’s hardware, checkfor the following conditions:• If you boot the system to the BIOS boot mode after installing an operatingsystem from the UEFI Boot Manager, the system will hang. The reverse isalso true. You must boot to the same boot mode in which you installed theoperating system. See "Using the System Setup Program and UEFI BootManager" on page 53.• Invalid memory configurations could cause the system to halt at startupwithout any video output. See "System Memory" on page 106.For all other startup issues, note the system messages that appear onscreen.See "System Messages" on page 38 for more information.Troubleshooting External ConnectionsEnsure that all external cables are securely attached to the externalconnectors on your system before troubleshooting any external devices.See Figure 1-1 and Figure 1-4 for the front-panel and back-panel connectorson your system.
