Dell EMC Inspiron 3671 Service Manual page 51

9. Remove the eight screws (#6-32x6.35) that secure the system board to the chassis.
10. Remove the screw (#6-32x4.8, standoff) that secures the system board to the chassis.
11. Remove the screw (#6-32x6.35) that secures the front-I/O bracket to the chassis.
12. Remove the front-I/O bracket from the front-I/O slot on the chassis.
Removing the system board 51