GT-I9300 - IMEI NULL/NULL, unknown baseband and no USB interfacing
 

Hi all,
some days ago I got a Samsung S3 GT-I9300, it didin't charge battery or power ON at all .Now, after chancing the microUSB connector, phone is charging and working fine but , since some pads (which carry data+ and data - USB signals on motherboard) are irreparably damaged and I don't know any alternartive points, I can't interfacing it to a pc via USB (phone is not rooted).The problems is the mobile is pretty useless as is since no SIM is detected (IMEI is NULL/NULL),in the device infos I can read only:

BASEBAND UNKNOWN
ANDROID VERSION 4.1.2
KERNEL VERSION 3.0.31-1314436
BUILD VERSION JZO45K.I9300XXEMG4

What can i do?It would be possible to root it (and try some restore) without connecting it to a PC?Is JTAG the only chance?
Thanks in advance