After working inside your computer..........................9 BitLocker..................................9 Chapter 2: Removing and installing components................10 Recommended tools................................10 Screw list..................................... 10 Major components of Inspiron 15 3521..........................11 Secure Digital (SD) Card..............................13 Removing the secure digital card ..........................13 Installing the secure digital card ..........................13 Base cover................................... 14 Removing the base cover............................14...
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Removing the system board thermal plate ......................38 Installing the system board thermal plate ......................38 Touchpad.....................................39 Removing the touchpad ............................39 Installing the touchpad ..............................40 Display assembly................................42 Removing the display assembly ..........................42 Installing the display assembly ..........................44 Display hinge caps................................
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Deleting or changing an existing system setup password.................93 Clearing BIOS (System Setup) and System passwords..................94 Chapter 5: Troubleshooting......................95 Handling swollen Lithium-ion batteries........................95 Dell SupportAssist Pre-boot System Performance Check diagnostics............... 95 Running the SupportAssist Pre-Boot System Performance Check..............96 Built-in self-test (BIST)..............................96 M-BIST...................................96 LCD Power rail test (L-BIST)...........................
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 For this reason, some previously approved methods of handling parts are no longer applicable.
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.
Transporting sensitive components When transporting ESD sensitive components such as replacement parts or parts to be returned to Dell, it is critical to place these parts in anti-static bags for safe transport. After working inside your computer About this task NOTE: Leaving stray or loose screws inside your computer may severely damage your computer.
Removing and installing components NOTE: The images in this document may differ from your computer depending on the configuration you ordered. Recommended tools The procedures in this document may require the following tools: ● Phillips screwdriver #0 ● Plastic scribe Screw list NOTE: When removing screws from a component, it is recommended to note the screw type, the quantity of screws, and...
● 3 ● ● I/O daughter-board M2x3.5 Power button M2x2 Power button with optional M2x2 fingerprint reader Power-adapter port M2.5x5 Major components of Inspiron 15 3521 The following image shows the major components of Inspiron 15 3521. Removing and installing components...
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1. Base cover 2. Battery 3. Speakers 4. Power button assembly 5. Touchpad assembly 6. Touchpad-assembly bracket 7. Power-adapter port 8. M.2 solid-state drive shield Removing and installing components...
18. Hard-disk drive NOTE: Dell provides a list of components and their part numbers for the original system configuration purchased. These parts are available according to warranty coverages purchased by the customer. Contact your Dell sales representative for purchase options.
About this task The following images indicate the location of the secure digital card and provide a visual representation of the installation procedure. Steps Slide the secure digital card into the secure digital card slot until it clicks into place. Next steps 1.
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Steps 1. Remove the six screws (M2x5) that secure the base cover to the palm-rest and keyboard assembly. 2. Loosen the two captive screws that secure the base cover to the palm-rest and keyboard assembly. 3. Using a plastic scribe, pry open the base cover starting from the recesses, which are located in the U-shaped indents at the top edge of the base cover, near the hinges.
Installing the base cover Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the base cover and provide a visual representation of the installation procedure. Removing and installing components...
Steps 1. Connect the battery cable to the connector on the system board. 2. Place the base cover on top of the palm-rest and keyboard assembly. 3. Align the screw holes on the base cover with the screw holes on the palm-rest and keyboard assembly, and snap the base cover latches into place.
● If the battery gets stuck inside your computer as a result of swelling, do not try to release it as puncturing, bending, or crushing a lithium-ion battery can be dangerous. In such an instance, contact Dell technical support for assistance. See www.dell.com/contactdell.
NOTE: Before removing the 3-cell battery, disconnect and remove the hard-drive flexible flat cable from its connector on the system board to avoid tugging of the 3-cell battery on the hard-drive flexible flat cable. 3. Disconnect and remove the battery cable from the 3-cell battery. Installing the 3-cell battery Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Removing the 4-cell battery Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. About this task The following image indicates the location of the 4-cell battery and provides a visual representation of the removal procedure. Steps 1.
Installing the 4-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 4-cell battery and provides a visual representation of the installation procedure. Steps 1.
NOTE: When replacing the 4-cell battery, use a plastic scribe to push downward into the bottom-left screw hole to insert the battery rubber stopper into the slot on the new replacement 4-cell battery. 2. Connect the battery cable to the 4-cell battery. 3.
Steps 1. Using a plastic scribe, carefully pry the memory-module retention clips, securing the memory module to its slot, until the memory module pops-up. 2. Lift at an angle and remove the memory module from the memory-module slot on the system board. Installing the memory module Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Steps 1. Align the notch on the memory module with the tab on the memory-module slot on the system board. 2. Slide the memory module firmly into the memory-module slot at an angle. 3. Press down on the memory module to snap it into place on the system board. Ensure that the memory-module retention clips have locked the memory module into place.
The following images indicate the location of the M.2 2230 solid-state drive and provide a visual representation of the removal procedure. Steps 1. Remove the screw (M2x2) that secures the M.2 2230 solid-state drive thermal plate to the palm-rest and keyboard assembly.
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Steps 1. Align the notch on the M.2 2230 solid-state drive with the tab on the M.2 card slot on the system board. 2. Slide the M.2 2230 solid-state drive into the M.2 card slot on the system board. 3. Place the M.2 2230 solid-state drive thermal plate on the M.2 2230 solid-state drive. NOTE: When installing the M.2 2230 solid-state drive thermal plate on the system, tuck the tabs on the M.2 2230 solid-state drive thermal plate under the hooks on the palm-rest and keyboard assembly.
4. Verify if the storage device is installed correctly: a. Turn on or restart your system. b. Press F2 when the Dell logo is displayed on the screen to enter the system setup (BIOS) program. NOTE: A list of storage devices is displayed under the System Information in the General group.
Installing the M.2 2280 solid-state drive Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the M.2 2280 solid-state drive and provide a visual representation of the installation procedure.
4. Verify if the storage device is installed correctly: a. Turn on or restart your system. b. Press F2 when the Dell logo is displayed on the screen to enter the system setup (BIOS) program. NOTE: A list of storage devices are displayed under the System Information in the General group.
Steps 1. Lift the latch and disconnect the hard-drive flexible flat cable from the system board. 2. Remove the four screws (M2x3.5) that secure the hard-drive assembly to the palm-rest and keyboard assembly. 3. Lift the hard-drive assembly along with its interposer and flexible flat cable from the palm-rest and keyboard assembly. 4.
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Steps 1. Align and slide the hard drive into the hard-drive bracket. 2. Align the screw holes on the hard-drive bracket with the screw holes on the hard drive. 3. Replace the four screws (M3x3) to secure the hard drive to the hard-drive bracket. 4.
Wireless card Removing the wireless card Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. About this task The following images indicate the location of the wireless card and provide a visual representation of the removal procedure. Steps 1.
Installing the wireless card Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task The following images indicate the location of the wireless card and provide a visual representation of the installation procedure. Steps 1.
Next steps 1. Install the base cover. 2. Install the secure digital card. 3. Follow the procedure in After working inside your computer. Speakers Removing the speakers Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card.
2. Unroute and remove the speaker cable from the routing guides on palm-rest and keyboard assembly. 3. Lift the speakers along with the cable off the palm-rest and keyboard assembly. Installing the speakers Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure. About this task NOTE: If the rubber grommets are pushed out when removing the speakers, push them back in before replacing the...
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Steps 1. Using the alignment posts and rubber grommets, place the speakers into the slots on the palm-rest and keyboard assembly. NOTE: Ensure that the alignment posts are threaded through the rubber grommets on the speakers. 2. Route the speaker cable along the bottom side of the palm-rest and keyboard assembly, over the WLAN antenna cables. Then secure the speaker cable into the routing guides on the palm-rest and keyboard assembly.
2. Install the secure digital card. 3. Follow the procedure in After working inside your computer. System board thermal plate Removing the system board thermal plate Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card.
About this task NOTE: If either the system board or the system board thermal plate is replaced, use the thermal grease provided in the kit to ensure that thermal conductivity is achieved. The following image indicates the location of the system board thermal plate and provides a visual representation of the installation procedure.
Steps 1. Disconnect and remove the hard-drive flexible flat cable from the connector on the system board. 2. Remove the three screws (M2x2) that secure the touchpad bracket in place to the palm-rest and keyboard assembly. 3. Slide and lift the touchpad bracket off the touchpad assembly. 4.
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Steps 1. Align and place the touchpad along with the touchpad flexible flat cable into its slot on the palm-rest and keyboard assembly. 2. Replace the two screws (M2x2) to secure the touchpad to the palm-rest and keyboard assembly. 3. Connect the touchpad flexible flat cable to the connector on the system board. 4.
Display assembly Removing the display assembly Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. 4. Remove the wireless card. About this task The following images indicate the location of the display assembly and provide a visual representation of the removal procedure. Removing and installing components...
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Steps 1. Disconnect the display cable and the speaker cable from the respective connectors on the system board. Removing and installing components...
2. Unroute the speaker cable and WLAN antenna cables from the respective routing guides on the palm-rest and keyboard assembly. 3. Open the display assembly at an angle of 90 degrees and place the system on the edge of a flat surface such that the palm-rest and keyboard assembly lay flat on the surface and the display assembly is over the edge.
NOTE: The power-adapter port is secured in place by the left display hinge. There is no screw, tape, or adhesives securing the power-adapter port to the palm-rest. As a result, technicians should take note of whether the power- adapter port has fallen out of the system during subsequent removal procedures. 2.
About this task The following images indicate the location of the display hinge caps and provide a visual representation of the removal procedure. Steps 1. Place the system on the edge of a flat surface and gently open the display hinges to at least 90 degrees. 2.
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About this task The following images indicate the location of the display hinge caps and provide a visual representation of the installation procedure. Steps 1. Align the rib inside the right-hinge cap to the left-outer side of the right hinge. 2.
Display bezel Removing the display bezel Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. 4. Remove the wireless card. 5. Remove the display assembly. 6. Remove the display hinge caps.
Installing the display bezel 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 display bezel and provides a visual representation of the installation procedure. Steps 1.
Display hinges Removing the display hinges Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. 4. Remove the wireless card. 5. Remove the display assembly. 6. Remove the display hinge caps.
2. Lift and remove the left hinge from the display assembly. 3. Remove the three screws (M2.5x3.8) that secure the right hinge to the display panel and back cover. 4. Lift and remove the right hinge from the display assembly. Installing the display hinges Prerequisites If you are replacing a component, remove the existing component before performing the installation procedure.
Next steps 1. Install the display bezel. 2. Install the display hinge caps. 3. Install the display assembly. 4. Install the wireless card. 5. Install the base cover. 6. Install the secure digital card. 7. Follow the procedure in After working inside your computer.
Steps 1. Using a plastic scribe, pry the display panel from the bottom-right corner. 2. Using your hands, gently pry the display panel from the tabs along the right side of the display back-cover. 3. Repeat step 1 and 2 for the left side of the display panel assembly. 4.
Steps 1. Place the display panel and display assembly on a clean and flat surface. 2. Connect the display cable to the connector at the back of the display panel and close the latch to secure the cable. 3. Adhere the tape to secure the display-cable connector latch to the back of the display panel. 4.
6. Remove the display hinge caps. 7. Remove the display bezel. 8. Remove the display hinges. 9. Remove the display panel. About this task The following images indicate the location of the camera module and provide a visual representation of the removal procedure. Steps 1.
Steps 1. Using the alignment post, adhere the camera module on the display back-cover and antenna assembly. 2. Connect the camera cable to its connector on the camera module. Next steps 1. Install the display panel. 2. Install the display hinges.
Steps 1. Disconnect the display eDP cable from its connector on the camera module. 2. Carefully peel off and remove the display eDP cable from the display back-cover. Installing the display cable 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 display cable and provides a visual representation of the installation procedure.
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Steps 1. Adhere the display eDP cable to the display back-cover. 2. Connect the display eDP cable to its connector on the camera module. Next steps 1. Install the display panel. 2. Install the display hinges. 3. Install the display bezel.
System board Removing the system board Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. 4. Remove the memory module. 5. Remove the M.2 2230 solid-state drive or the M.2 2280 solid-state drive, whichever applicable.
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NOTE: When removing the system board to replace/access other parts, the system board can be removed with the system board thermal plate attached to it in order to simplify the procedure and preserve the thermal bond between the system board and system board thermal plate. The following images indicate the location of the system board and provide a visual representation of the removal procedure.
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Steps 1. Disconnect the following cables from the system board: a. I/O daughter-board FFC b. Power-adapter port cable c. Keyboard FFC d. Keyboard-backlight FFC, if applicable NOTE: This step applies only to systems shipped with a keyboard backlight installed. e. Touchpad FFC f.
2. Remove the screw (M2x2) and the three screws (M2x3.5) that secure the system board to the palm-rest and keyboard assembly. NOTE: When removing the system board with the system board thermal plate, remove the two screws (M2x5) that secure the system board thermal plate to the palm-rest and keyboard assembly. 3.
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The following images indicate the location of the system board and provide a visual representation of the installation procedure. Removing and installing components...
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Steps 1. Place the system board (with the system board thermal plate, if applicable) on the palm-rest and keyboard assembly. 2. Align the screw holes on the system board with the screw holes on the palm-rest and keyboard assembly. NOTE: When installing the system board with the system board thermal plate, replace the two screws (M2x5) to secure the system board thermal plate to the palm-rest and keyboard assembly.
3. Replace the screw (M2x2) and the three screws (M2x3.5) to secure the system board to the palm-rest and keyboard assembly. 4. Connect the following cables to the system board: a. I/O daughter-board FFC b. Power-adapter port cable c. Keyboard FFC d.
3. Remove the base cover. About this task The following image indicates the location of the I/O daughter-board flexible flat cable and provides a visual representation of the removal procedure. Steps 1. Lift the latch and disconnect the I/O daughter-board flexible flat cable from the connector on the I/O daughter-board. 2.
Steps 1. Place the I/O daughter-board flexible flat cable on the palm-rest and keyboard assembly. 2. Connect the I/O daughter-board flexible flat cable to the connector on the system board. 3. Close the latch on the I/O daughter-board flexible flat cable connector to secure it to the system board. 4.
Steps 1. Remove the two screws (M2.5x5) that secure the right hinge in place to the palm-rest and keyboard assembly. 2. Lift the right hinge away from the palm-rest and keyboard assembly to access the I/O daughter-board. 3. Lift the latch and disconnect the I/O daughter-board flexible flat cable from the connector on the I/O daughter-board. 4.
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Steps 1. Place the I/O daughter-board under the right hinge and on the palm-rest and keyboard assembly. 2. Align the screw holes on the I/O daughter-board to the screw holes on the palm-rest and keyboard assembly. 3. Replace the three screws (M2x3.5) to secure the I/O daughter-board to the palm-rest and keyboard assembly. 4.
Power button Removing the power button Prerequisites 1. Follow the procedure in Before working inside your computer. 2. Remove the secure digital card. 3. Remove the base cover. 4. Remove the wireless card. 5. Remove the display assembly. 6. Remove the daughter-board.
Steps 1. Place the power button into its slot on the palm-rest and keyboard assembly. 2. Align the screw hole on the power button to the screw hole on the palm-rest and keyboard assembly. 3. Replace the screw (M2x2) to secure the power button to the palm-rest and keyboard assembly. Next steps 1.
Steps 1. Remove the two screws (M2.5x5) that secure the right hinge in place to the palm-rest and keyboard assembly. 2. Lift the right hinge away from the palm-rest and keyboard assembly to access the power button with optional fingerprint reader.
Steps 1. Place the power button with optional fingerprint reader into its slot on the palm-rest and keyboard assembly. 2. Align the screw hole on the power button with optional fingerprint reader to the screw hole on the palm-rest and keyboard assembly.
About this task The following images indicate the location of the power-adapter port and provide a visual representation of the removal procedure. Steps 1. Remove the two screws (M2.5x5) that secure the left hinge in place to the palm-rest and keyboard assembly. 2.
Steps 1. Align and place the power-adapter port into its slot on the palm-rest and keyboard assembly. NOTE: The power-adapter port is secured in place by the left display hinge. There is no screw, tape, or adhesives securing the power-adapter port to the palm rest. As a result, technicians should take note of whether the power- adapter port has fallen out of the system during subsequent removal procedures.
9. Remove the display panel. 10. Remove the camera. 11. Remove the display cable. About this task NOTE: The display back-cover and antenna assembly cannot be further disassembled once all the pre-removal parts procedures are completed. If the wireless antennas are malfunctioning and are required to be replaced, replace the entire display back-cover and antenna assembly.
Steps Place the display back-cover and antenna assembly on a flat surface and perform the post-requisites to install the display back-cover and antenna assembly. Next steps 1. Install the display cable. 2. Install the camera. 3. Install the display panel. 4.
6. Remove the 2.5-inch hard-disk drive, if applicable. NOTE: This procedure applies only to systems shipped with a 2.5-inch hard-disk drive installed. 7. Remove the wireless card. 8. Remove the speakers. 9. Remove the 3-cell battery or the 4-cell battery, whichever applicable. 10.
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About this task NOTE: The system board can be installed with the system board thermal plate attached to it in order to simplify the procedure and preserve the thermal bond between the system board and system board thermal plate. The following image indicates the location of the palm-rest and keyboard assembly and provides a visual representation of the installation procedure.
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...
BIOS setup CAUTION: Unless you are an expert computer user, do not change the settings in the BIOS Setup program. Certain changes can make your computer work incorrectly. NOTE: Depending on the computer and its installed devices, the items listed in this section may or may not be displayed. NOTE: Before you change BIOS Setup program, it is recommended that you write down the BIOS Setup program screen information for future reference.
Table 3. Navigation keys (continued) Keys Navigation Moves to the previous page until you view the main screen. Pressing Esc in the main screen displays a message that prompts you to save any unsaved changes and restarts the system. One time boot menu To enter one time boot menu, turn on your computer, and then press F12 immediately.
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Table 4. System setup options—Main menu (continued) Main Keyboard Type Displays the type of keyboard installed on the system. Table 5. System setup options—Advanced menu Advanced Virtualization Enables or disables the Virtualization technology. Default: Enabled VI for Direct I/O Enables or disables the Virtualization technology for Direct I/O.
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Default: Disabled SupportAssist System Resolution Auto OS Recovery Threshold Controls the automatic boot flow for SupportAssist System Resolution Console and for the Dell OS Recovery tool. Default: 2 SupportAssist OS Recovery Enables or disables the boot flow for the SupportAssist OS Recovery tool in the even of certain system errors.
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Displays if the system password is clear or set. Default: Deactivate WINDOWS SMM SECURITY MITIGATIONS TABLE Enables or disables configuration of platform features on (WSMT) Dell Client Systems with WSMT-enabled BIOS. Default: Enabled Firmware TPM Enable or disable the firmware TPM. Default: Enabled...
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.
You can create a system password and a setup password to secure your computer. CAUTION: The password features provide a basic level of security for the data on your computer. CAUTION: Anyone can access the data that is stored on your computer if it is not locked and left unattended. NOTE: System and setup password feature is disabled.
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.
● Using a non-Dell or incompatible battery may increase the risk of fire or explosion. Replace the battery only with a compatible battery purchased from Dell that is designed to work with your Dell computer. Do not use a battery from other computers with your computer.
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. 4. Click the arrow at the bottom left corner.
LCD Built-in Self Test (BIST) Dell laptops have a built-in diagnostic tool that helps you determine if the screen abnormality you are experiencing is an inherent problem with the LCD (screen) of the Dell laptop or with the video card (GPU) and PC settings.
Check diagnostics. 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.
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.
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5. Press and hold the power button for 20 seconds to drain the flea power. 6. Install the battery. 7. Install the base cover. 8. Connect the power adapter to your computer. 9. Turn on your computer. NOTE: For more information about performing a hard reset, see the knowledge base article 000130881 www.dell.com/support. Troubleshooting...
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 12. Self-help resources Self-help resources Resource location Information about Dell products and services www.dell.com My Dell app...