QUOTE(ahzhen988 @ May 27 2015, 11:47 AM)
Ok i will try for it.Hopefully it is workÂ

I updated my hard disk driver when encountered similar problem with my External hard disk. I have encounter similar scenarios like told by most of the users, I have listed them here:-
1st issue : One of my right port not detecting my 3.0 usb hard diak but working fine with my 2.0 usb pendrive. Which concludes that it may have not enough power on that particular port. Fixed it by shut down for few minutes + unplugged electric.
2nd issue: My external hard disk 3.0 usb stopped working, external hdd works on 2.0 usb only but not turning to 3.0 usb <-- (checked using LED indicator on HDD and file transfer speed.). Tried restarting couple of times and tried updating windows but problem not solved. At last solved by re installing updated HDD driver that comes with it. Then works fine as before.
Usually it will be fixed on restart. If no then I would suggest you to update your USB drivers to the latest one and try and try changing to different usb cables. I think the usb port not have enough power to transfer data or maybe other probs.
Or maybe (just a second thought, no heart fillings)
-> maybe your MicroUSB port on samsung s3 has oxidation issue which will cause your mobile with the problems.
if you found that your s3 have that oxidation problem on MicroUSB port then check out this video
https://www.youtube.com/watch?v=pmpmH4NyG-4 
All the best
This post has been edited by MgrSagaaboyz: May 27 2015, 01:01 PM