Thanks for your reply.
I had examined the port on the phone with a light and magnifying glass. I found nothing wrong and after comparing cable connections I still couldn't find any thing that would cause the problem.
Another writer had talked about using a toothpick to remove buildup the caused his connection problem. After reading that and despite having already looked for something blocking the connection, I did exactly what he did and immediately found a ball of lint/stuff in one corner of the port. I was amazed how much came out.
Problem solved. My main fear was that the port on the phone was damaged but this process showed just how well the phone was manufactured.
thanks to all for their help.