9Troubleshooting your systemSafety first—for you and your systemCAUTION: Many repairs may only be done by a certified service technician. You should onlyperform troubleshooting and simple repairs as authorized in your product documentation, or asdirected by the online or telephone service and support team. Damage due to servicing that isnot authorized by Dell is not covered by your warranty. Read and follow the safety instructionsthat are shipped with your product.Troubleshooting system startup failureIf you boot the system to the BIOS boot mode after installing an operating system from the UEFI BootManager, the system stops responding. To avoid this issue, you must boot to the same boot mode inwhich you installed the operating system.For all other startup issues, note the system messages that appear on the screen.Troubleshooting external connectionsBefore troubleshooting any external devices, ensure that all external cables are securely attached to theexternal connectors on your system before troubleshooting any external devices.Troubleshooting the video subsystem1. Check the system and power connections to the monitor.2. Check the video interface cabling from the system to the monitor.3. Run the appropriate diagnostic test.If the tests run successfully, the problem is not related to video hardware.If the tests fail, see the Getting help section.Troubleshooting a USB devicePrerequisitesNOTE: Follow steps 1 to 6 to troubleshoot a USB keyboard or mouse. For other USB devices, go tostep 7.197
