SGS3 USB not connecting to PC I have a Samsung Galaxy S3, running Android 4.1.1.

I am having problems connecting the phone to my PC. I can connect other S3 phones to my PC. So, I presume that it is not the PC (Windows 7) that has problems.

I am using the original Samsung cable. The URT is set to modem and USB is set to PDA.
I had the same problem: phone was charging OK but not recognized as external device.
I found this solution on the Internet and it worked in my case:


Power off your phone
Power on the phone in Download mode (Volume Down + Home + Power)
Press Volume Up to continue in Download mode -> you should see an Android bot and some informations about your OS (rooted or standard, ...)
Plug your phone into your computer using your USB cable
Windows should now discover it and load the driver (from Windows update)
Power off your phone
Power on the phone (classically this time)