Why will phone not charge when connected to charger?

My Xperia X10 Mini E10i has worked well for the past 3-4 years, but in recent weeks will only charge if I wiggle the charger around in the slot until eventually the orange light shines, and it begins to charge. Now it seems impossible to establish any contact between the phone and the charger. Could the charging point have become loose within the phone? What repairs could I possibly perform to solve this problem?