Dell Latitude 5490, Руководство по обслуживанию

Страница: 103 / 105

Table 21. Diagnostic LED behavior (continued)
Blinking pattern
Problem description Suggested resolution
Amber White
2 8 LCD power rail failure Replace the system board.
3 1 CMOS battery failure Reset the CMOS battery connection.
If problem continues, replace the RTS
battery.
3 2 PCI, video card/chip failure Replace the system board.
3 3 Recovery image not found Flash the latest BIOS version. If problem
continues, replace the system board.
3 4 Recovery image found but invalid Flash the latest BIOS version. If problem
continues, replace the system board.
3 5 Power-rail failure EC ran into power sequencing failure. If
problem continues, replace the system
board.
3 6 System BIOS Flash incomplete Flash corruption detected by BIOS. If
problem continues, replace the system
board.
3 7 Management Engine (ME) error Timeout error displayed while waiting on
ME to reply to HECI message. If problem
continues, replace the system board.
4 1 Memory DIMM power rail failure Replace the system board.
4 2 CPU power cable connection issue Initiate PSU BIST. If problem persists,
replace the system board.
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 .
WiFi power cycle
About this task
If your computer is unable to access the internet due to WiFi connectivity issues a WiFi power cycle procedure may be
performed. The following procedure provides the instructions on how to conduct a WiFi power cycle:
NOTE: Some ISPs (Internet Service Providers) provide a modem/router combo device.
Steps
1. Turn off your computer.
2. Turn off the modem.
3. Turn off the wireless router.
Troubleshooting 103