Acer AN515-51 Service Manual page 174

Attach the screw to secure the USB board to the upper case.
3.
NOTE: Screw torque force = 1.5~2.0kgf.cm
Connect the USB board FFC to the mainboard connector and secure the latch.
4.
5-36
Figure 5-49. Securing the Screw
Figure 5-50. Connecting the USB Board FFC
Service and Maintenance