USB connection mode disappeared

[Antomex]

Hi,

I'm trying to change the MTP/MSC connection on my phone because when I plug it with the PC (and with Sony PC Companion installed), the phone isn't detected (windows says: device not recognized) but it only charge the battery.

I have called the Xperia assistance (italian ones) and they have said me that I have to change the type of connection from MTP to MSC (or viceversa I don't remember).
They have said that I can change the type of connection under Settings > Xperia™ > USB Connectivity > USB connection mode.

But I can't find this USB connection mode.

So, how can I solve my problem?

For the connection problem I have tried to:

• Turn on DEBUG MODE, but nothing.
• Plug the phone with another PC (a new one that I have, with windows 8 and Sony PC companion installed), but nothing.
• Using a VM with Windows XP, but nothing.
• Hammering the phone, but nothing!!
  

I have noticed this thing: Before 4.1.2 Android update, I was able to connect, using an OTA cable, an USB pen drive to my phone. Now, with android 4.1.2, the USB pen drive isn't detected.

Here some specifics about my phone:

Model Number: LT26i

Android version: 4.1.2

Build Number: 6.2.B.1.96

Here some specifics about my PC:

SO: Windows 7 enterprise 64 bit

[gwhispererz]

Since nothing works, send phone to service centre to have it checked.

[Antomex]

yes I think that is the only solution, thanks for the support!

[gwhispererz]

No problem, you are welcome.

[BP6737]

Xperia S .... went to backup phone and the complete menu options for USB Connection Mode are GONE!

Does anyone know if factory reset fixes this?

Phone is running ICS 4.0.4.