I run Linux (Ubuntu 12.04), and I have a Galaxy Nexus running Android 4.0.4. (Purchased in December 2011.) When I plug the phone in to the PC via USB there is no detection whatsoever. Tailing /var/log/syslog when plugging or unplugging the phone there is ZERO activity in the logs.
The phone however will charge.
Plugging the phone into a Windows 7 machine, same deal. Phone charges off USB but Windows never prompts to say the device has been detected. Also same on MAC.
Using the same micro USB cable, and an HTC One X. Linux, Windows and Mac all detect the HTC phone AND the phone charges.
I have been to Settings -> Storage
and changed the phone from PTP to MTP, still no change.
From memory this is the first time I have ever wanted to plug the phone into the PC. So it may have never worked.
Is there something I am missing (like a setting or something?) or can I assume that the phone is faulty?