Recovering The Operating System; Real-Time Clock (Rtc Reset) - Dell NOT21988 Owner's Manual

Table 45. Diagnostic-light LED codes (continued)
Blinking pattern
Amber
3
3
3
NOTE: Blinking 3-3-3 LEDs on Lock LED (Caps-Lock or Nums-Lock), Power button LED (without Fingerprint reader), and
Diagnostic LED indicates failure to provide input during LCD panel test on Dell SupportAssist Pre-boot System Performance
Check diagnostics.
Camera status light: Indicates whether the camera is in use.
● Solid white—Camera is in use.
● Off—Camera is not in use.
Caps Lock status light: Indicates whether Caps Lock is enabled or disabled.
● Solid white — Caps Lock enabled.
● Off — Caps Lock disabled.

Recovering the operating system

When your computer is unable to boot to the operating system even after repeated attempts, it automatically starts Dell
SupportAssist OS Recovery.
Dell SupportAssist OS Recovery is a standalone tool that is preinstalled in all Dell computers installed with Windows operating
system. It consists of tools to diagnose and troubleshoot issues that may occur before your computer boots to the operating
system. It enables you to diagnose hardware issues, repair your computer, back up your files, or restore your computer to its
factory state.
You can also download it from the Dell Support website to troubleshoot and fix your computer when it fails to boot into their
primary operating system due to software or hardware failures.
For more information about the Dell SupportAssist OS Recovery, see Dell SupportAssist OS Recovery User's Guide at
www.dell.com/serviceabilitytools. Click SupportAssist and then, click SupportAssist OS Recovery.

Real-Time Clock (RTC Reset)

The Real Time Clock (RTC) reset function allows you or the service technician to recover Dell systems from No POST/No
Power/No Boot situations. The legacy jumper enabled RTC reset has been retired on these models.
Start the RTC reset with the system powered off and connected to AC power. Press and hold the power button for twenty (20)
seconds . The system RTC Reset occurs after you release the power button.
132 Troubleshooting
White Problem description
5
6 SBIOS flash corruption
7
Power rail failure
ME error
Suggested resolution
● If problem persists,
replace the system board.
● Flash latest BIOS version.
● If problem persists,
replace the system board.
● Flash latest BIOS version.
● If problem persists,
replace the system board.
● Flash latest BIOS version.
● If problem persists,
replace the system board.