Dell Latitude 5421 Notebook Teardown removal guide for customer replaceable units (CRUS)

Steps to enter Service mode before working on your computer:

1. Turn the computer off.

2. Disconnect any telephone, network, USB and AC adapter cables from the computer.

3. While holding down the B key, turn the computer on using the power button.

4. When you see the owner tag appear on the screen, press any key on the keyboard.

5. When you see the ready to proceed messaging on the screen, again press any key on the keyboard.

6. The computer will turn off. At this point it's safe to remove and replace parts.

Steps to exit Service mode after working on your computer:

1. Insert the AC adapter cable to the computer.

2. Press the power button to start the computer booting.

3. The computer will boot to the operating system and exit service mode.

Pre-Removal instructions before removing the Base Cover:

1. During installation or removal of any hardware always ensures that all data is backed up properly.

2. Disconnect any telephone, network, or USB cables from the computer.

3. Disconnect the computer and all attached devices from their electrical outlets and enter Service Mode.

Turn the closed system upside down and Loosen the eight (8) captive screws in the base.

Using something non-metallic, pry the base cover starting from the hinges and pry open the left and right edges, before prying off the bottom of the cover to release it from the chassis.

Lift the cover away from the system.

Pre-Removal instructions before removing the Memory Module:

1. During installation or removal of any hardware always ensures that all data is backed up properly.

2. Disconnect any telephone, network, or USB cables from the computer.

3. Disconnect the computer and all attached devices from their electrical outlets and enter Service Mode.

4. Remove the Base Cover.

The memory is located in the middle of the chassis. Pull the metal retention clips away from either side of the DIMM.

The DIMM will pop up from the motherboard. Grip the DIMM and pull it out of the connector and the system.

Pre-Removal instructions before removing the M.2 Solid State Drive (SSD):

1. During installation or removal of any hardware always ensures that all data is backed up properly.

2. Disconnect any telephone, network, or USB cables from the computer.

3. Disconnect the computer and all attached devices from their electrical outlets and enter Service Mode.

4. Remove the Base Cover.

Pre-Removal instructions before removing the Wireless Network WLAN Card:

1. During installation or removal of any hardware always ensures that all data is backed up properly.

2. Disconnect any telephone, network, or USB cables from the computer.

3. Disconnect the computer and all attached devices from their electrical outlets and enter Service Mode.

4. Remove the Base Cover.

The Wireless Card is located in the middle of the chassis, to the left-hand side of the memory. Remove the single captive screw that secures the end of the WLAN card to the motherboard. Remove the securing bracket from the system.

Disconnect the antenna cables from the card. (These are pop stud connectors and lift off with a little pressure.) Pry the card from the adhesive pad, using a non-metallic probe, and pull the card out of the connector and the system.

Pre-Removal instructions before removing the Wireless Cellular WWAN Card:

1. During installation or removal of any hardware always ensures that all data is backed up properly.

2. Disconnect any telephone, network, or USB cables from the computer.

3. Disconnect the computer and all attached devices from their electrical outlets and enter Service Mode.

4. Remove the Base Cover.

The Wireless Cellular Card is located in the top left corner of the chassis. Remove the single screw that secures the end of the WWAN card to the motherboard. Remove the securing bracket from the system and disconnect the antenna cables from the card. (These are pop stud connectors and lift off with a little pressure.)

 With the WWAN card sitting up at an angle, pull the card out of the connector and the system.

Pre-Removal instructions before removing the microSD Card:

1. During installation or removal of any hardware always ensures that all data is backed up properly.

Push on the microSD card to have it pop out of the right-hand side edge of the system.

Grip the card and pull it out of the computer.

Pre-Removal instructions before removing the SIM Card Tray:

1. During installation or removal of any hardware always ensures that all data is backed up properly.

When you look at the system from the rear, the SIM Card slot is between the two hinges. Insert a SIM removal tool or pin into the hole in the SIM card tray. The tray will pop out enough for you to grip the tray and pull it out of the computer.