Maintenance and Service Guide

System board
NOTE: All system boards use the following part numbers:
xxxxxx-001: Non-Windows operating systems
xxxxxx-601: Windows 10 operating system
Description Spare part number
System board with integrated processor for use in models with discrete graphics memory:
Intel Xeon E-2186M processor L30971-001, -601
Intel Xeon E-2176M processor L30969-001, -601
Intel Core i7-8850H processor L33161-001, -601
Intel Core i7-8750H processor L33160-001, -601
Intel Core i5-8400H processor L33159-001, -601
Intel Core i5-8300H processor L33158-001, -601
System board with integrated processor for use in models with UMA graphics memory:
Intel Core i7-8850H processor L28657-001, -601
Intel Core i7-8750H processor L28656-001, -601
Intel Core i5-8400H processor L31685-001, -601
Intel Core i5-8300H processor L31684-001, -601
Before removing the system board, follow these steps:
1. Turn o the computer. If you are unsure whether the computer is o or in Hibernation, turn the
computer on, and then shut it down through the operating system.
2. Disconnect the power from the computer by unplugging the power cord from the computer.
3. Disconnect all external devices from the computer.
4. Remove the bottom cover (see Bottom cover on page 33).
5. Remove the battery (see Battery on page 35).
6. If installed, remove the WWAN module (see WWAN modules on page 44).
7. If a separate WLAN module is installed, remove the WLAN module (see WLAN/Bluetooth combo card
on page 46).
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 (as applicable):
Solid-state drive (see Solid-state drive (M.2) on page 37 or Optane memory module (Optane memory
module on page 39)
Memory module (see Memory module on page 40)
Remove the system board:
1. Remove the three Phillips M2.0×4.0 screws (1) from the USB Type-C/power connector bracket, and then
lift the bracket o the system board (2).
Component replacement procedures 59