Troubleshooting; Power Lights; Diagnostic Lights - Dell Precision R5400 Service Manual

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Troubleshooting
Dell Precision™ R5400 Service Manual
Tools
Dell Diagnostics
Solving Problems
Dell Technical Update Service
CAUTION: Only trained service technicians are authorized to remove the computer cover and access any of the components inside the computer.
Before working inside your computer, read the safety information that shipped with your computer. For additional safety best practices
information, see the Regulatory Compliance Homepage at www.dell.com/regulatory_compliance.
CAUTION: Always unplug your computer from the electrical outlet before opening the cover.
Tools

Power Lights

The power button light located on the front of the computer illuminates and blinks or remains solid to indicate different states:
If the power light is green and the computer is not responding, see
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If the power light is blinking green, the computer is in standby mode. Press a key on the keyboard, move the mouse, or press the power button to
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resume normal operation.
If the power light is off, the computer is either turned off or is not receiving power.
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Reseat the power cable into both the power connector on the back of the computer and the electrical outlet.
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If the computer is plugged into a power strip, ensure that the power strip is plugged into an electrical outlet and that the power strip is turned
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on.
Bypass power protection devices, power strips, and power extension cables to verify that the computer turns on properly.
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Ensure that the electrical outlet is working by testing it with another device, such as a lamp.
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Ensure that the main power cable and front panel cable are securely connected to the system board (see
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If the power light is steady amber, a device may be malfunctioning or incorrectly installed.
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Remove and then reinstall the memory modules (see
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Remove and then reinstall any cards (see
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Eliminate interference. Some possible causes of interference are:
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Power, keyboard, and mouse extension cables
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Too many devices on a power strip
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Multiple power strips connected to the same electrical outlet
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Diagnostic Lights

CAUTION: Before working inside your computer, read the safety information that shipped with your computer. For additional safety best
practices information, see the Regulatory Compliance Homepage on www.dell.com at www.dell.com/regulatory_compliance.
To help troubleshoot a problem, your computer has four lights labeled 1, 2, 3, and 4 on the front panel. When the computer starts normally, the lights flash,
and then turn off. If the computer malfunctions, use the sequence of the lights to help identify the problem.
NOTE: After the computer completes POST, all four lights turn off before booting to the operating system.
Diagnostic Light Codes During POST
Light Pattern Problem Description
The computer is in a normal off
condition or a possible pre-BIOS
failure has occurred.
Diagnostic Lights.
System Memory).
Expansion Cards).
Suggested Resolution
Plug the computer into a working electrical outlet and press the power button.
System Board).