Command

Turn OFF HDMI output

sudo /opt/vc/bin/tvservice -o

Turn ON HDMI output

sudo /opt/vc/bin/tvservice -p

Turn OFF USB chip

echo '1-1' |sudo tee /sys/bus/usb/drivers/usb/unbind

Turn ON USB chip

echo '1-1' |sudo tee /sys/bus/usb/drivers/usb/bind