No, I didn't try it...anyway, it happened everywhere...
It fell sometimes, but never something serious...i thought it was the antenna because, while removing the antenna cover to change the front panel, I noticed two small scratches on the circuit, due to putting on and taking off the cover...
Well, now the problem is solved...I tried to put in my 8310 the sim that I was using at the moment (on another phone, because obviously I couldn't stay 20 days without a phone), and it worked perfectly...I don't know why, maybe the sim I put before in the 8310 to test the new antenna was too old or deactivated, it can be the reason for the SOS message and no signal...
Now it seems to work properly, thank you for the help anyway