**I only suggest this if you're Xbox controller is not under warranty, proceeding with this fix will void your warranty on the controller**
You will need
Drill
Good half mm drill bit
Small Phillips head screw driver
A paper clip
Standard hex set
On both grips of the controller there are snap in place panels you will need to remove them. There are five keyed screws on the controller (two under each snap together panel and one under the label of the battery compartment.) Take your drill and bit then slightly drill the dot out of the the center of each keyed screw. Use your hex tool and and unscrew the screws then carefully separate the two pieces apart with the face of the controller facing down. Once separated with the face down take the first circuit board off (be careful of breaking small wires and losing the jack it's self because it's not fused to the bord) the 3.5 mm jack has pins on the bottom of it that reaches the contact points on the board. Very carefully bend those pins slightly up to make a better connection. Take the paperclip and carefully bend the pins inside of the jack (it will be visible and reachable through the top of the jack) inward towards the center of the jack. When you are finished you will have to set the jack back in its groove on the face of the controller then replace the top board and ensure all connections are tight, then continue to reassemble the controller. This should work to resolve this issue. I have successfully done this on my own controller.