Power button LED behavior
On certain Dell Latitude systems, the power button LED is used to provide an indication of the system status, and as a result the power
button illuminates when pressed. The systems with the optional power button/fingerprint reader will have no LED under the power button
and hence will apply the available LED's in the system to provide an indication of the system status.
Power button LED behavior without Fingerprint reader
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System is ON (S0) = LED illuminates solid white.
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System in Sleep/Standby (S3, SOix) = LED is off
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System is Off/Hibernating (S4/S5) = LED is off
Power On and LED behavior with Fingerprint reader
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Pressing the power button for a duration between 50 msec to 2 sec turns on the device.
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Power button does not register additional presses until the SOL (Sign-Of-Life) has been provided to the user.
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System LED's illuminates upon pressing the power button.
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All the available LED's (Keyboard backlit/ Keyboard caps lock LED/ Battery Charge LED) illuminates and displays specified behavior.
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The auditory tone is Off by default. It can be enabled in the BIOS setup.
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Safeguards do not time out if the device gets hung during the logon process.
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Dell logo: Turns on within 2 secs after pressing the power button.
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Full boot: Within 22 secs after pressing the power button.
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Below is the example timelines:
Technology and components
15
Summary of Contents for Latitude 3540
Page 1: ...Dell Precision 3540 Service Manual Regulatory Model P80F Regulatory Type P80F001 ...
Page 19: ...2 Pry the base cover from the edge using a plastic scribe 1 2 Disassembly and reassembly 19 ...
Page 42: ...4 Lift the speaker up out of the computer 42 Disassembly and reassembly ...
Page 80: ...4 Carefully close the LCD screen 80 Disassembly and reassembly ...
Page 95: ...2 Gently snap the display bezel into place Disassembly and reassembly 95 ...
Page 102: ...102 Disassembly and reassembly ...
Page 115: ...6 Turn on the modem 7 Turn on your computer Troubleshooting 115 ...
