I am having a problem with one of my Motorola cellphones, Model V547. I cannot make or receive calls. It seems that a youngster pulled-off the original antenna and switched it with a similarly-looking antenna. The new antenna seems to fit into the socket perfectly but the phone doesn't make/receive calls. Should I purchase a new antenna? I see people selling antennas at street fairs with blinking lights, how do I know if any of those antennas would work? Thanks.