Dell NOT21684 Owner's Manual page 103

Steps
1. Place the palm-rest assembly at the edge of the table with the speakers facing away from the edge.
2. Align the screw holes on the palm-rest assembly with the screw holes on the display hinges.
3. Replace the six screws (M2.5x5) that secure the left and right display hinges to the palm-rest assembly.
4. Connect the sensor-board cable to the connector on the system board.
5. Cover the sensor-board cable with the black flap near the antenna cables.
6. Route the WLAN and WWAN antennas (where applicable) from the routing guides on the system board.
7. Connect the display cable to the system board.
8. Adhere the tape that secures the display cable to the system board.
9. Align the screw holes on the display-cable bracket with the screw holes on the system board.
10. Replace the two (M2x3) screws that secure the display cable bracket to the system board.
Next steps
1. Install the WLAN card.
2. Install the 4G WWAN card
3. Install the base cover.
4. Install the SIM card.
5. Follow the procedure in
102 Removing and installing Field Replaceable Units (FRUs)
or 5G WWAN card, as applicable.
After working inside your computer.