The charging port on my LG Optimus G (E970) phone was having trouble getting any power. Only one of my several power cords was able to charge; even then, it had to be at a specific angle and would swap between charging/not-charging every few seconds.
The only way to effectively charge it was to disable all radios, disable the screen-on-when-charging-state-changes option, plug it in and pray. Luckily, the custom ROM I use exposes that option so I was able to charge enough to do a full nandroid backup before starting the repair.
Smooth like butter. This phone is very well built, yet still easy to pull apart and put back together. The repair took roughly an hour, even when I was also distracted with my 3-year old running around.
At one point, I accidentally turned the phone on while taking it apart. I turned it around and saw the screen on with a "system server has stopped" force crash message. Oops! I set the phone to power down and continued the repair.
Be careful not to hold the power button when bracing the phone and unscrewing/unlatching pieces of the internals.