56 Quick Reference GuideDiagnostic LightsCAUTION: Before you begin any of the procedures in this section, follow thesafety instructions located in the Product Information Guide.To help you troubleshoot a problem, your computer has four lights labeled 1,2, 3, and 4 on the front or back panel. The lights can be off or green. Whenthe computer starts normally, the patterns or codes on the lights change asthe boot process completes. When the computer starts normally, the patternsor codes on the lights change as the boot process completes. If the POSTportion of system boot completes successfully, all four lights display solidgreen. If the computer malfunctions during the POST process, the patterndisplayed on the LEDs may help identify where in the process the computerhalted.NOTE: The orientation of the diagnostic lights may vary depending on the systemtype. The diagnostic lights can appear either vertical or horizontal.N O T A B O O T D I S K E T T E — Insert a bootable floppy disk and restart yourcomputer.USB O V E R C U R R E N T E R R O R — Disconnect the USB device. Use an externalpower source for the USB device.NOTICE - H A R D DR I V E SELF MONITORING SYSTEM H A S R E P O R T E D T H A T AP A R A M E T E R H A S E X C E E D E D I T S N O R M A L O P E R A T I N G R A N G E . DE L LR E C O M M E N D S T H A T Y O U B A C K U P Y O U R D A T A R E G U L A R L Y. A P A R A M E T E R O U TO F R A N G E M A Y O R M A Y N O T I N D I C A T E A P O T E N T I A L H A R D D R I V E P R O B L E M —S.M.A.R.T error, possible HDD failure. This feature can be enabled or disabled inBIOS setup.