Installing The System Board - Dell Latitude 9420 Service Manual

NOTE: Flip open the display cable latch from the two tabs on the top side of the latch. Hold the left and right sides of
the cable's connector head and gently disconnect the display cable in a direct upward motion to prevent damage to the
connector.
5. Disconnect the left speaker cable from the connector on the system board.
6. Disconnect the Proximity sensor RF board FPC cable from the connector on the system board.
7. Disconnect the clickpad FPC cable from the connector on the system board.
8. Disconnect the LED board FPC cable from the connector on the system board.
9. Disconnect the system fan cable from the connector on the system board.
10. Loosen the single captive screw that secures the WWAN Darwin cable bracket to the system board.
11. Lift the WWAN Darwin cable bracket off the system board.
12. Use a plastic scribe and disconnect the two WWAN Darwin cables from the connectors on the system board.
CAUTION: Disconnect the Darwin cables from the system board in a direct upward motion to prevent damage
to the connector's pins.
13. Unroute the white/gray WWAN main antenna cable and black/gray WWAN antenna cable from the metal clips on the system
board.
14. Remove the three (M2x4) screws that secures the USB Type-C bracket to the system board.
15. Remove the four (M1.6x2.5) screws that secure the system board to the palm-rest assembly.
CAUTION: Do not remove the screw which is used to secure the base cover hook in place.
16. Hold the left side of the system board and partially lift the system board from the system.
CAUTION: To prevent obstructions while lifting the system board, you should clear the area around the
system board of cables, FFCs, FPCs, and any adhesive items.

Installing the system 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 system board and provides a visual representation of the installation procedure.
Removing and installing components 49