Dell Latitude 7420 Service Manual page 51

Steps
1. Replace the system board into the computer chassis and tighten it using the single (M2x2.5) screw (for computer
configuration with fingerprint reader on power button) or four (M2x2.5) screws (for computer configuration without
fingerprint reader), two (M2x4) screws, and two (M2x3) screws securing the system board in place.
2. Connect the speakers board FPC, tweeter cable, audio board FFC, touchpad FFC, USH board FFC and, LED board FFC to
the system board.
3. Connect the display, camera, touch screen and, sensor board cables to the system board and route them along the guiding
tabs.
4. Replace the display cable bracket on the system board and secure it using the two (M2x2) screws.
5. Route the WWAN antenna cables along the rubber guides on the system board and connect it to the WWAN card.
6. Connect the WLAN antenna cables to the WLAN module on the system board.
7. Replace the WLAN antenna bracket and secure it to the system board using the single (M2x2) screw.
8. Connect the fingerprint reader FPC to the system board.
9. Replace the finger print reader bracket and secure to the system board using the single (M2x2.5) screw.
10. Place the WWAN antenna cable bracket and replace the M2x2.5 screw.
Next steps
1. Install the heatsink assembly.
2. Install the battery.
3. Install the WWAN card.
4. Install the solid-state
5. Install the base cover.
6. Install the SIM card.
7. Install the microSD card.
8. Follow the procedure in
drive.
after working inside your computer.
Removing and installing components 51