M919V 5.0.1 unlock help

hello

Phone must be powered on.
2. Type *#0808# and select 'DM+MODEM+ADB'.
3. Type *#9090# and choose USB (or 'DM/DUN over HSIC').
4. Reboot phone.



i use this method but computer cant detect phone

" unknwon device "


plz help