Dear Sunny,
I called you right now but I know it's very late.
First can you tell them lens cable is properly connected ?
Lens shift up/down & left/right were moved ?
Which type of lens ?
You can do manually (1.0-1.4 )
Please see attached two pictures, first take out 4 screw in front then you can takeout lens black plastic cover, the you can access zoom and focus gear. Don't forget to loose zoom and focus lock.
I hope this could help,
Thanks and Regards,
Jun