I bought my S3 in July and after 2 weeks I noticed it wouldn't charge. This was an off-and-on problem for a while until it completely stopped charging altogether. I'd leave it on the charger over night and the next day it said 100%, but once taken off the charger it immediately dropped down to 45%. I tried everything to fix the problem. I did a factory reset - didn't work. I made sure to disable sync - didn't work. I powered the phone off while charging - didn't work.
Then I called Samsung and shipped it off for them to fix. In the shipment I included the battery, the factory charger, & the phone. They replaced some "component". I got it back yesterday and the problem still continued (Note I had to use a Tracphone aka "A Burner" for a week and a half until my phone arrived).
The phone recognizes the factory charger when it's plugged into the power outlet or USB port of the computer. It also recognizes the car charger. Still nothing works. So I'm doing a warranty exchange through T-Mobile and hoping the newer phone doesn't have the same problem.
This has been a very long and annoying process. I cursed out the Samsung representative because I was so frustrated. I told him, "This is some bullshit and if there is a problem with my battery or charger then they should have known because I mailed that in along with the phone."
I almost feel bad, but if I'm going to suffer from this problem then their representatives just have to deal with it. I ought to call them back now just for the hell of it.
