Contents Chapter 1: Safety instructions.......................6 Before working inside your computer..........................6 Before you begin ................................7 Safety precautions................................7 Electrostatic discharge—ESD protection........................7 ESD field service kit ................................8 Transporting sensitive components..........................9 After working inside your computer..........................9 Chapter 2: Removing and installing components................10 Recommended tools................................10 Screw list.....................................
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Wireless card..................................37 Removing the wireless card............................37 Installing the wireless card............................38 Camera assembly................................40 Removing the camera assembly..........................40 Installing the camera assembly..........................41 Bottom cover..................................42 Removing the bottom cover............................. 42 Installing the bottom cover............................43 Power-supply unit................................44 Removing the power-supply unit (PSU)........................44 Installing the power-supply unit (PSU)........................46 Power-supply fan................................
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Clearing BIOS (System Setup) and System passwords..................100 Chapter 5: Troubleshooting......................101 Display built-in self test..............................101 SupportAssist diagnostics.............................. 101 Running the SupportAssist Pre-Boot System Performance Check............... 101 Diagnostics..................................102 Recovering the operating system..........................103 WiFi power cycle................................103 Flea power release................................104 Chapter 6: Getting help and contacting Dell................105 Contents...
You should only perform troubleshooting and repairs as authorized or directed by the Dell technical assistance team. Damage due to servicing that is not authorized by Dell is not covered by your warranty. See the safety instructions that is shipped with the product or at www.dell.com/regulatory_compliance.
ESD protection is an increasing concern. Due to the increased density of semiconductors used in recent Dell products, the sensitivity to static damage is now higher than in previous Dell products. For this reason, some previously approved methods of handling parts are no longer applicable.
● Catastrophic – Catastrophic failures represent approximately 20 percent of ESD-related failures. The damage causes an immediate and complete loss of device functionality. An example of catastrophic failure is a memory DIMM that has received a static shock and immediately generates a "No POST/No Video" symptom with a beep code emitted for missing or nonfunctional memory.
It is recommended that all field service technicians use the traditional wired ESD grounding wrist strap and protective anti-static mat at all times when servicing Dell products. In addition, it is critical that technicians keep sensitive parts separate from all insulator parts while performing service and that they use anti-static bags for transporting sensitive components.
Removing and installing components NOTE: The images in this document may differ from your computer depending on the configuration you ordered. Topics: • Recommended tools • Screw list • Major components of your computer • Stand • Cable cover—optional • Back cover •...
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Some systems have magnetic surfaces. Ensure that the screws are not left attached to such surface when replacing a component. NOTE: Screw color may vary with the configuration ordered. Table 1. OptiPlex 5490 All-in-One screw list Component Screw type Quantity Screw image Cable cover—optional...
Before working inside your computer. CAUTION: When servicing the system, place it on an elevated, clean, and flat surface. Dell Technologies recommends removing the stand to avoid accidental damage to the system display during servicing. About this task The following image provides a visual representation of the fixed stand removal procedure.
1. Follow the procedure in Before working inside your computer. CAUTION: When servicing the system, place it on an elevated, clean, and flat surface. Dell recommends removing the stand to avoid accidental damage to the system display during servicing. Removing and installing components...
About this task The following image provides a visual representation of the height adjustable stand removal procedure. Steps 1. Press and slide the release button up. 2. Hold the button in the release position, and lift the stand upward. 3. Slide the stand downward, to lift the stand off the back cover. Installing the height adjustable stand Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Align the tabs on the stand with the slots on the back cover. 2. Slide the stand upward until it clicks into place. Next steps 1. Follow the procedure in After working inside your computer. Cable cover—optional Removing the cable cover Prerequisites 1.
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Steps 1. Unroute the power cable from the slots on the cable cover. 2. Remove the screw (M3x5) that secures the cable cover to the bottom cover. 3. Lift the cable cover from the bottom cover. Removing and installing components...
Installing the cable cover Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image provides a visual representation of the cable cover installation procedure: Removing and installing components...
Steps 1. Route the power cable through the slots on the cable cover. 2. Align the screw hole on the cable cover with the screw hole on the bottom cover. 3. Replace the screw (M3x5) to secure the cable cover to the bottom cover. Next steps 1.
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Steps 1. Press and hold the release tab on the back cover to release it from the latch on the system-board shield. 2. Slide the back cover up to release the tabs on the cover from the slots on the middle frame. 3.
Installing the back cover Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image provides a visual representation of the back cover installation procedure. Removing and installing components...
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Steps 1. Place the back cover on the middle frame and system-board shield and align the tabs on the back cover with the slots on the middle frame. 2. Slide the back cover to lock the release tab under the latch on the system-board shield. Next steps 1.
2. Install the stand. 3. Follow the procedure in After working inside your computer. Hard drive Removing the hard drive Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the stand. 3. Remove the cable cover (optional).
Steps 1. Press down the tab securing the hard-drive assembly to the system-board shield. 2. Slide and lift the hard-drive assembly from the slot on the display-assembly base. 3. Pry the tabs on hard-drive bracket from its slots on the hard drive. 4.
Steps 1. Align the tabs on the hard-drive bracket with the slots on the hard drive. 2. Flex the hard-drive bracket and replace the remaining tabs on the hard-drive bracket with the slots on the hard drive. 3. Place the hard-drive assembly into the slot and slide it to lock the hard-drive assembly on the display-assembly base. Next steps 1.
NOTE: Repeat step 2 and 3 if there are two memory modules. Installing the memory modules Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the memory module and provides a visual representation of the installation procedure.
System-board shield Removing the system-board shield Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the stand. 3. Remove the cable cover (optional). 4. Remove the back cover. About this task The following image indicates the location of the system-board shield and provides a visual representation of the removal procedure.
About this task The following image indicates the location of the system-board shield and provides a visual representation of the installation procedure. Steps 1. Align the screw holes on the system-board shield with the screw holes on the display-assembly base. 2.
5. Remove the system-board shield. About this task The following image indicates the location of the M.2 2230 solid-state drive and provides a visual representation of the removal procedure. Steps 1. Remove the screw (M2x2.5) that secures the solid-state drive to the system board. 2.
Steps 1. Align the notch on the solid-state drive with the tab on the M.2 card slot. 2. Slide the solid-state drive into the M.2 card slot on the system board. 3. Replace the screw (M2x2.5) to secure the solid-state drive to the system board. Next steps 1.
Steps 1. Remove the screw (M2x2.5) that secures the solid-state drive to the system board. 2. Slide and remove the solid-state drive from the M.2 card slot on the system board. Installing the M.2 2280 solid-state drive Prerequisites CAUTION: Solid-state drives are fragile. Exercise care when handling the solid-state drive. If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Align the notch on the solid-state drive with the tab on the M.2 card slot. 2. Slide the solid-state drive into the M.2 card slot on the system board. 3. Replace the screw (M2x2.5) to secure the solid-state drive to the system board. Next steps 1.
Steps 1. Disconnect the system-fan cable from the system board. 2. Remove the three screws (M3x5) that secure the system fan to the display-assembly base. 3. Lift the system fan, along with its cable, off the display-assembly base. Installing the system fan Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Align the screw holes on the system fan with the screw holes on the display-assembly base. 2. Replace the three screws (M3x5) to secure the system fan to the display-assembly base. 3. Connect the system-fan cable to the connector on the system board. Next steps 1.
Steps 1. Using the plastic scribe, press on the metal clip to release the coin-cell battery from the coin-cell battery holder. 2. Lift the coin-cell battery from the coin-cell battery holder. Installing the coin-cell battery Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the coin-cell battery and provides a visual representation of the installation procedure.
Steps With the positive-side facing up, insert the coin-cell battery into the battery holder on the system board and gently press the battery until it snaps into place. Next steps 1. Install the system-board shield. 2. Install the back cover. 3.
Steps 1. Remove the two screws (M2x2.5) that secure the wireless-card shield to the system board. 2. Unroute the antenna cables from the routing guides on the wireless-card shield. 3. Lift the wireless-card shield out of the system. 4. Remove the screw (M2x2.5) that secures the wireless-card bracket to the wireless card. 5.
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Steps 1. Connect the antenna cables to the wireless card. The following table provides the antenna-cable color scheme: Table 2. Antenna-cable color scheme Connectors on the Antenna-cable color Silkscreen marking wireless card △ (white triangle) Main White MAIN Auxiliary Black ▲...
5. Follow the procedure in After working inside your computer. Camera assembly Removing the camera assembly Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the stand. 3. Remove the cable cover (optional). 4. Remove the back cover.
Steps 1. Remove the two screws (M3x5) that secure the camera-assembly door to the display-assembly base. 2. Disconnect the camera cable from the connector on the system board. 3. Remove the two screws (M3x5) that secure the camera assembly to the middle frame. 4.
2. Slide the camera assembly on the middle frame, and align the screw holes on the camera assembly with the screw holes on the middle frame. 3. Replace the two screws (M3x5) to secure the camera assembly to the middle frame. 4.
Steps 1. Remove the four screws (M3x5) that secure the bottom cover to the display-assembly base. 2. Pry and lift the bottom cover off the display-assembly base. Installing the bottom cover Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the bottom cover and provides a visual representation of the installation procedure.
Steps 1. Align the screw holes on the bottom cover with the screw holes on the display-assembly base. 2. Replace the four screws (M3x5) to secure the bottom cover to the display-assembly base. Next steps 1. Install the system-board shield. 2.
Steps 1. Remove the screw (M3x5) that secures the power-supply socket to the rear-I/O bracket. 2. Slide the power-supply socket out of the rear-I/O bracket. 3. Remove the power-supply cable from the routing guides on the rear-I/O bracket and PSU fan. 4.
Steps 1. Align and place the PSU in the slot on the display-assembly base. 2. Replace the screw (M3x5) to secure the PSU to the display-assembly base. 3. Connect the power-supply cable to the connector on the system board. 4. Route the power-supply cable through the routing guides on the rear-I/O bracket and PSU fan. 5.
Steps 1. Remove the power-supply cable from the routing guides on the PSU fan. 2. Disconnect the PSU-fan cable from the system board. 3. Remove the two screws (M3x5) that secure the PSU fan to the display-assembly base. 4. Lift the PSU fan from the display-assembly base. Installing the PSU fan Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Align the screw holes on the PSU fan with the screw holes on the display-assembly base. 2. Replace the two screws (M3x5) to secure the PSU fan to the display-assembly base. 3. Connect the PSU-fan cable to the connector on the system board. 4.
About this task The following image indicates the location of the heat sink and provides a visual representation of the heat sink removal procedure. Steps 1. In reverse sequential order (as indicated on the heat sink), loosen the five captive screws that secure the heat sink to the system board and the display-assembly base.
Steps 1. Align the screw holes on the heat sink with the screw holes on the system board and the display-assembly base. 2. In sequential order (as indicated on the heat sink), tighten the five captive screws that secure the heat sink to the system board and display-assembly base.
About this task The following image indicates the location of the heat sink and provides a visual representation of the heat sink removal procedure. Steps 1. In reverse sequential order (as indicated on the heat sink), loosen the nine captive screws that secure the heat sink to the system board and the display-assembly base.
Steps 1. Align the screw holes on the heat sink with the screw holes on the system board and the display-assembly base. 2. In sequential order (as indicated on the heat sink), tighten the nine captive screws to secure the heat sink to the system board and display-assembly base.
6. Remove the heat sink. About this task The following image indicates the location of the processor and provides a visual representation of the removal procedure. Steps 1. Press the release lever down and then push it away from the processor to release it from the securing tab. 2.
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Steps 1. Ensure that the release lever on the processor socket is fully extended in the open position. NOTE: The pin-1 corner of the processor has a triangle that aligns with the triangle on the pin-1 corner on the processor socket.
Rear-I/O bracket Removing the rear-I/O bracket Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the stand. 3. Remove the cable cover (optional). 4. Remove the back cover. 5. Remove the system-board shield. 6. Remove the bottom cover.
Installing the rear-I/O bracket Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the rear-I/O bracket and provides a visual representation of the installation procedure.
System board Removing the system board Prerequisites 1. Follow the procedure in Before working inside your computer. NOTE: Your computer’s Service Tag is stored in the system board. You must enter the Service Tag in the BIOS setup program after you replace the system board. NOTE: Replacing the system board removes any changes you have made to the BIOS using the BIOS setup program.
Steps 1. Disconnect the display back-light cable from the connector on the system board. 2. Disconnect the display cable from the connector on the system board. 3. Disconnect the PSU cable from the connector on the system board. 4. Disconnect the PSU fan cable from the connector on the system board. 5.
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Steps 1. Align the screw holes on the system board with the screw holes on the display-assembly base. 2. Replace the nine screws (M3x5) to secure the system board to the display-assembly base. Removing and installing components...
3. Connect the camera cable to the connector system board. 4. Connect the touchscreen cable to the system board. 5. Connect the system fan cable to the system board. 6. Connect the audio-board cable to the system board. 7. Connect the SIO-power cable to the system board. 8.
About this task The following image indicates the location of the speakers and provides a visual representation of the removal procedure. Steps 1. Disconnect the speaker cable from the connector on the system board. 2. Remove the six screws (M3 4+7.1xZN) that secure the speakers to the display-assembly base. 3.
Steps 1. Align the screw holes on the speakers with the screw holes on the display-assembly base. 2. Replace the six screws (M3 4+7.1xZN) to secure the speakers to the display-assembly base. 3. Route the speaker cable through the routing guide on display-assembly base and connect the speaker cable to the system board.
5. Remove the system-board shield. 6. Remove the bottom cover. 7. Remove the rear-I/O bracket. 8. Remove the speakers. About this task The following image indicates the location of the power-button board and provides a visual representation of the power-button board removal procedure.
Steps 1. Align and place the power-button board in the slot on the middle frame. 2. Replace the screw (M3x5) to secure the power-button board to the middle frame. 3. Slide the power-button board cable into the connector on the system board and close the latch to secure the cable. Next steps 1.
6. Remove the bottom cover. 7. Remove the rear-I/O bracket. 8. Remove the speakers. About this task The following image indicates the location of the microphones and provides a visual representation of the removal procedure. Steps 1. Disconnect the microphone cable from the system board, and unroute it from the routing guides on the display-assembly base.
Steps 1. Align the screw holes on the microphone modules with the screw holes on the middle frame. 2. Replace the two screws (M2X2.5) to secure the microphone modules to the middle frame. 3. Route the microphone cable through the routing guides on the display-assembly base and connect the microphone cable to the system board.
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5. Remove the hard drive. 6. Remove the system-board shield. 7. Remove the bottom cover. 8. Remove the rear-I/O bracket. About this task The following image indicates the location of the side I/O-board and provides a visual representation of the removal procedure. Steps 1.
Installing the side I/O-board Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the side I/O-board and provides a visual representation of the installation procedure.
Next steps 1. Install the speakers. 2. Install the rear-I/O bracket. 3. Install the bottom cover. 4. Install the system-board shield. 5. Install the hard drive. 6. Install the back cover. 7. Install the cable cover (optional). 8. Install the stand. 9.
Installing the audio board Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the audio board and provides a visual representation of the removal procedure. Steps 1.
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4. Remove the back cover. 5. Remove the system-board shield. 6. Remove the wireless card. 7. Remove the bottom cover. 8. Remove the rear-I/O bracket. 9. Remove the speakers. About this task The following image indicates the location of the antenna modules and provides a visual representation removal procedure of the antenna modules.
Steps 1. Remove the antenna cables from the routing guides on the display-assembly base. 2. Remove the two screws (M2x2.5) that secure the antenna modules to the middle frame. 3. Carefully peel the copper foil that secures the antenna cables to the middle frame. 4.
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Steps 1. Align and place the antenna modules in the slots on the middle frame. 2. Adhere the copper foil that secures the antenna cables to the middle frame. 3. Replace the two screws (M2x2.5) to secure the antenna modules to the middle frame. 4.
Next steps 1. Install the speakers. 2. Install the rear-I/O bracket. 3. Install the bottom cover. 4. Install the wireless card. 5. Install the system-board shield. 6. Install the back cover. 7. Install the cable cover (optional). 8. Install the stand. 9.
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Steps 1. Remove the 12 screws (M3x5) that secure the display panel to the middle frame and display-assembly base. 2. Unroute the display back-light cable from the routing guides on the display-assembly base. 3. Place the system in an upright position. Removing and installing components...
4. Holding the top corner, release the display panel away from the middle frame and display-assembly base. 5. Route the display back-light and display cable through the slots on the display-assembly base. 6. Lift the display panel up from the middle frame and display-assembly base. Installing the display panel Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
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Steps 1. Place the system in an upright position, and slide the display panel on the slots of the display-assembly base. 2. Route the display-backlight, and display cable through the slots on the display-assembly base. 3. Place the display-assembly base on a clean and flat surface with the display panel facing down. 4.
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Table 3. Number of jig screws (continued) Display type Number of jig screws Non-touch Three display 6. Route the display back-light cable in the routing guides on the display-assembly base. Next steps 1. Install the fan. 2. Install the PSU. 3.
5. Install the speakers. 6. Install the rear-I/O bracket. 7. Install the bottom cover. 8. Install the hard drive. 9. Install the system-board shield. 10. Install the back cover. 11. Install the cable cover (optional). 12. Install the stand. 13. Follow the procedure in After working inside your computer.
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Steps 1. Remove the 17 screws (M3x5) that secure the middle frame to the display-assembly base. 2. Remove the middle frame and lift the middle frame off the display-assembly base. Removing and installing components...
Installing the middle frame Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following image indicates the location of the middle frame and provides a visual representation of the middle frame installation procedure.
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Steps 1. Slide and align the middle frame to the slots on the display-assembly base, then snap the middle frame into place on the display-assembly base. 2. Replace the 17 screws (M3x5) to secure the middle frame to the display-assembly base. Next steps 1.
Drivers and downloads When troubleshooting, downloading or installing drivers it is recommended that you read the Dell Knowledge Based article, Drivers and Downloads FAQ 000123347. Drivers and downloads...
Boot Sequence allows you to bypass the System Setup–defined boot device order and boot directly to a specific device (for example: optical drive or hard drive). During the Power-on Self-Test (POST), when the Dell logo appears, you can: ● Access System Setup by pressing F2 key ●...
NOTE: Depending on your computer and its installed devices, the items listed in this section may or may not appear. Table 4. System setup options—System information menu Overview OptiPlex 5490 All-in-One BIOS Version Displays the BIOS version number. Service Tag Displays the Service Tag of the computer.
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Table 4. System setup options—System information menu (continued) Overview Memory Information Memory Installed Displays the total computer memory installed. Memory Available Displays the total computer memory available. Memory Speed Displays the memory speed. Memory Channel Mode Displays single or dual channel mode. Memory Technology Displays the technology used for the memory.
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Table 6. System setup options—Integrated Devices menu Integrated Devices Date/Time Displays the current date in MM/DD/YYYY format and current time in HH:MM:SS AM/PM format. Camera Enables or disable the camera. By default, the Enable Camera option is selected Audio Enable Audio Enable or disable the integrated audio controller.
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Table 7. System setup options—Storage menu (continued) Storage By default, the Secure Digital (SD) Card option is enabled. Secure Digital (SD) Card Read-Only Mode Enable or disable the SD card read-only mode. By default, the Secure Digital (SD) Card Read-Only Mode option is not enabled.
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Table 10. System setup options—Power menu (continued) Power AC Behavior AC Recovery Enables the system to turn on automatically, when AC is inserted. By default, the Power Off option is enabled. Block Sleep Enables to block entering sleep (S3) mode in the operating system. By default, the Block Sleep option is disabled.
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By default, the option is disabled. Allow Non-Admin PSID Revert Enable Allow Non-Admin PSID Revert Controls access to the Physical Security ID (PSID) revert of NVMe hard-drives from the Dell Security Manager prompt. By default, the option is disabled. System setup...
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By default, the option is enabled. Dell Auto OS Recovery Threshold Controls the automatic boot flow for SupportAssist System Resolution Console and for Dell OS Recovery Tool. By default, the threshold value is set to 2. Table 14. System setup options—System Management menu...
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Table 14. System setup options—System Management menu (continued) System Management Keyboard Errors Enable Keyboard Error Detection Numlock LED Enable Numlock LED Enable or disable Numlock LED. By default, the option is enabled. Table 15. System setup options—Keyboard menu Keyboard Keyboard Errors Enable Keyboard Error Detection Enable or disable the keyboard error detection.
Steps 1. Go to www.dell.com/support. 2. Click Product support. In the Search support box, enter the Service Tag of your computer, and then click Search. NOTE: If you do not have the Service Tag, use the SupportAssist feature to automatically identify your computer. You can also use the product ID or manually browse for your computer model.
One-Time boot menu on the computer. Most of the Dell computers built after 2012 have this capability, and you can confirm by booting your computer to the F12 One-Time Boot Menu to see if BIOS FLASH UPDATE is listed as a boot option for your computer. If the option is listed, then the BIOS supports this BIOS update option.
● USB drive formatted to the FAT32 file system (key does not have to be bootable) ● BIOS executable file that you downloaded from the Dell Support website and copied to the root of the USB drive ● AC power adapter that is connected to the computer ●...
Clearing BIOS (System Setup) and System passwords About this task To clear the system or BIOS passwords, contact Dell technical support as described at www.dell.com/contactdell. NOTE: For information on how to reset Windows or application passwords, refer to the documentation accompanying Windows or your application.
SupportAssist Pre-Boot System Performance Check. Running the SupportAssist Pre-Boot System Performance Check Steps 1. Turn on your computer. 2. As the computer boots, press the F12 key as the Dell logo appears. 3. On the boot menu screen, select the Diagnostics option. Troubleshooting...
7. Select the device from the left pane and click Run Tests. 8. If there are any issues, error codes are displayed. Note the error code and validation number and contact Dell. Diagnostics Power status indicator light: Indicates the power status.
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.
4. Wait for 30 seconds. 5. Turn on the wireless router. 6. Turn on the modem. 7. Turn on your computer. Flea power release About this task Flea power is the residual static electricity that remains on the computer even after it has been powered off and the battery has been removed.
Getting help and contacting Dell Self-help resources You can get information and help on Dell products and services using these self-help resources: Table 22. Self-help resources Self-help resources Resource location Information about Dell products and services www.dell.com Tips Contact Support In Windows search, type Contact Support, and press Enter.