Steps
1. Power off your computer.
2. Disconnect any peripherals connected to your computer. Connect only the supplied AC power adapter to your computer.
3. Ensure that the LCD screen is clean with no dust particles on the surface of the screen.
4. From the power-off state, press and hold the D key and power button to enter LCD BIST mode. Continue to hold the D key,
until you see color bars on the LCD screen.
5. The screen displays multiple color bars and the entire screen changes to red, green and blue. During this process, carefully
inspect the screen for any abnormalities.
6. Press Esc to exit.
NOTE: LCD BIST is also initiated when Enhanced Pre-Boot System Assessment (ePSA) diagnostics is launched. For
more information about ePSA, see Dell EPSA Diagnostic 3.0.
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.
4. Wait for 30 seconds.
5. Turn on the wireless router.
6. Turn on the modem.
7. Turn on your computer.
Drain residual flea power (perform hard reset)
About this task
Flea power is the residual static electricity that remains in the computer even after it has been powered off and the battery is
removed.
For your safety, and to protect the sensitive electronic components in your computer, you are requested to drain residual flea
power before removing or replacing any components in your computer.
Troubleshooting
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