My S3 had been charging very erratically. It would take 10-20 hours to report a full charge but would then discharge in just a few hours. Most interesting was the fact that it would only 'try' to charge on MY USB cable; other cables and chargers were not recognized.
Exploring the issue, I found links concerning debris in the charging port (on the phone) that led me to more carefully look inside the USB, male connector. I found that one of the five connectors was broken off. I am quite sure that the broken connector ended up inside the charging port, shorting out other connectors. Its location apparently allows SOME connectivity between my cable and the port but interfered with the connectivity of other, undamaged USB cables.
I cleaned out the port and replaced the damaged USB cable. While I didn't see any connector debris falling out, the phone is now charging properly.
The Take Away Lessons: check inside your charging connector and look for damage. Check inside your charging port. Look for and clear out debris.
Exploring the issue, I found links concerning debris in the charging port (on the phone) that led me to more carefully look inside the USB, male connector. I found that one of the five connectors was broken off. I am quite sure that the broken connector ended up inside the charging port, shorting out other connectors. Its location apparently allows SOME connectivity between my cable and the port but interfered with the connectivity of other, undamaged USB cables.
I cleaned out the port and replaced the damaged USB cable. While I didn't see any connector debris falling out, the phone is now charging properly.
The Take Away Lessons: check inside your charging connector and look for damage. Check inside your charging port. Look for and clear out debris.