0. Have you tried restarting or performing a soft reset on your Lumia 1520? Does your phone still charge?
1. It appears that the problem is with your phone, particularly the mini-USB port - thanks for the definitive information.
2.a. Check that there is no accumulated dirt in the port. If there is, use a piece of folded paper to try to clean it (do not use hard metallic objects - we don't want to damage or misalign the pins).
2.b. Use an aspirator to force air into the port, in an attempt to blow the dirt out. Use a can of compressed air if necessary. Do NOT blow into the port using your mouth and straw (moisture may get into the phone, and we all know what would happen next).
If these don't work, you may need to bring your phone to a service center, informing them accurately about your findings - so they would know exactly what to do.