HP EliteBook 840 G9 Maintenance And Service Manual page 80

Before removing the system board, follow these steps:
1. Prepare the computer for disassembly (see
2. Remove the bottom cover (see
3. Remove the battery (see
4. Remove the fan (see
When you replace the system board, be sure to remove the following components from the defective system
board and install them on the replacement system board:
WWAN module (see
●
WLAN module (see
●
Memory modules (see
●
Solid-state drive (see
●
Heat sink (see
●
RTC battery (see
●
Remove the system board:
1. Release the ZIF connector (1) to which the connector board cable is connected, and then disconnect the
connector board cable from the system board.
2. Disconnect the webcam cable (2) from the system board.
3. Carefully disconnect the WWAN module antenna cables (3) from the WWAN module.
NOTE:
that identify them with a number that corresponds to a terminal on the WWAN module. Connect the
antenna cable to the corresponding WWAN module terminal.
4. Disconnect the display panel cable (4) from the system board.
5. Release the display panel cable from the retention clips (5) that are built into the computer.
6. Carefully disconnect the WLAN module antenna cables (6) from the WLAN module.
NOTE:
the #1 white WLAN module antenna cable connects to the WLAN module #1 Main terminal. The #2 black
WLAN module antenna cable connects to the WLAN module #1 Aux terminal.
7. Release the WLAN module antenna cables from the retention clips (7) that are built into the computer.
8. Disconnect the following cables from the system board:
Speaker cables (8)
●
Keyboard ZIF cable (9)
●
Card reader ZIF cable (10)
●
Touchpad ZIF cable (11)
●
74 Chapter 5 Removal and replacement procedures for authorized service provider parts
Bottom cover on page
Battery on page
Fan on page 59).
WWAN module on page
WLAN module on page
Memory modules on page
Solid-state drive on page
Heat sink on page 76).
Fingerprint reader on page
Computer models have one to four WWAN module antenna cables. The antenna cables have tags
Computer models have either one or two WLAN module antennas. On models with two antennas,
Preparation for disassembly on page
45).
47).
48).
50).
52).
54).
77).
45).