Samsung phone wont connect as USB Storage

[AllenHe]

When I connect the phone to the computer via USB cable, it shows that the device is connected as a media device, and when I select for other USB options only Camera(PTP) is available. But I need it to connect as USB storage so I can test run app on my phone. I have tried turning the USB debugging on, but doesn't seen to work. Anyone has a solution?
My phone's android system is Jellybean.

 

[256bits]

Try keeping the phone turned OFF. See if that works. On some, that is the only way the files show up on computer screen.

 

[AllenHe]

Hmm thanks Ill try. :D