Lenovo B490 Hardware Maintenance Manual page 67

Removal steps of system board assembly and USB board
1
Remove the screws , and then detach the connectors as shown in the following illustration.
Step Screw (quantity)
1
M2 × 6 mm, flat-head, nylon-coated (2)
When installing: Ensure that all the connectors are attached firmly.
Remove the system board in the direction shown by the arrows
Color Torque
Black 1.85 kgf-cm
10 and 11 . Then detach the DC-in cable
.
Chapter 7 Removing and replacing a FRU
12 .
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