My N900's antenna is working very bad, not in every call, but very often.
The signal is full, 3g,2.5g,2g, but this changes nothing.
I've open the device with the level 1-2 guide and i've unmount the antenna two-three times.

My questions are:
is there a method to test my antenna?
is it possibile that is a software-related problem?
did I have broke something by opening my device?
where can I buy a new antenna?

thanks!