1. Enter the engineer mode => Device => Set UART => UART setting .
2. On TST-PS Config make it UART 2 , 115200
3. On PS config make it USB Port , 115200
4. On TST-L1 Config make it none.
5. Press Ok, the phone will shut down,
6. Start the phone, when you connect it to the computer it will be in com-port automatically.
7. If you want the previous setting "mass storage or picture or webcam" change the PS Config to UART 1 and press ok.