HP ProDesk 400 G4 Small Form Factor (SFF) - Maintenance and Service Guide

System board
NOTE: The system board spare park kit includes replacement thermal material.
Follow these steps to remove the system board:
1. Prepare the computer for disassembly (see Preparation for disassembly on page 23).
2. Remove the access panel (see Access panel on page 24), and then remove the following components:
a. Drive cage (see Drive cage on page 28)
b. Expansion card (see Expansion card on page 35)
c. Fan cowling (see Fan cowling on page 38)
d. Fan-sink (see Fan-sink on page 39)
NOTE: When replacing the system board, be sure that the following components are removed from
the defective system board and installed on the replacement system board:
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WLAN module (see WLAN module on page 32)
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Memory module (see Memory module on page 34)
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Expansion card (see Expansion card on page 35)
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Processor (see Processor on page 41)
3. Disconnect the speaker cable (1) from the system board.
4. Disconnect the wireless antenna cables (2) from the terminals on the WLAN module.
NOTE: The wireless antenna cable labeled "1/MAIN" connects to the WLAN module "Main" terminal.
The wireless antenna cable labeled "2/AUX" connects to the WLAN module "Aux" terminal.
5. Disconnect the power supply cable (3) from the system board.
42 Chapter 4 Removal and replacement procedures