Poor radio reception

[AA77]

Fiat 500 2010 - I have seen lots of threads about poor radio reception. Thanks to all the info I have replaced the roof antenna and base, also added a new connector plug to the aerial cable at the radio end. All I can pick up is one FM station (Heart).

I have now removed the aerial plug at the back of the radio and inserted a small electrical screwdriver into the socket at the back of the radio and now I can get all FM stations.

Does this suggest the complete aerial lead needs replacing (from front of car to back) or would it suggest there is a problem with the radio (specifically the aerial plug socket)?

Many thanks.