[Q] Where to make changes for Enabaling Mass Storage topic

I am using jellybean 4.1.1 ROM which is great on my device but i cant connect my device through USB Mass storage ( it starts to connecting but stuck & again show turn USB On )
because rom which i am using is developed for other device which dont have internal memory &
i got cm 10 rom which has usb mass storage connction & internal SD Card is accessible through my phone
my question is How to enable mass storage on my device & where to make changes to enable mass storage ????