This issue can be fixed easily, you just have some stuff to fix it with. It's not only the connectors that's dirty, It's also the bottom of the micro usb port, it can easily be blocking the the connector from connecting all the way in. Here's how i fixed mine:
The first thing you'll need is some rubbing alcohol
Some Q-Tips.
The second thing you'll need is a very small sewing needle (go ask your grandma for one

)
The third optional thing you'll need is some compressed air WITH a straw thing at the end
First off, remove the battery of the phone and set it somewhere.
Then get your sewing needle and dip it into the rubbing alcohol (helps clean the residue).
Then DELICATELY take the needle and clean ALL residue on the bottom of the port. Do this and make sure ALL residue is gone.
Then take the Q-tip and dip it in the rubbing alcohol.
VERY GENTLY take the Q-Tip and put very little pressure against the charging port.
Take the needle and go for a second try for the residue and let it air dry, OR get the compressed air and CAREFULLY blow out the rubbing alcohol and dust out of the charging port.
Put the battery when dry and turn on phone.
This will effectively clean the charging port AND the bottom of the port.
This has probably an 80% chance of working. It worked for me!
Plug it in and see if that works!
I'M NOT RESPONSIBLE IF YOU MESS UP AND SCREW UP YOUR PHONE!!!!!
I hope this helped everybody
