Cell Phone Stuck in Headset Mode? Here's the Fix...
How to easily clean out your cell phone headphone jack
by Paul Ace Diamond "Huggy" Blow
The first thing you should try is to simply plug and unplug the headphones about 20 times or so. If this does not fix the "headset" mode problem, try a slimmed down Q-tip with some rubbing alcohol on it to clean the headphone jack. You can also try spraying some condensed air inside the headphone jack to free up any stuck particles or dirt. Then, plug and unplug the headphones 20 times or so. These steps have worked on my own cell phone in the past, but the last time my phone got stuck in "headset" mode, they failed to solve the problem.
Use Graphite powder to lubricate the headphone jack The best solution to cleaning and lubricating a cell phone's headphone jack to get it unstuck from "headset" mode is to buy a tube of Graphite powder lubricant (for $2-$3 a tube), give the tube a squirt of graphite powder into the headphone jack hole, and then plug in and unplug the headphones about 10-20 times. Do this with the cell phone turned off. Once turned on, your phone's headphone jack should be unstuck, and out of "headset" mode. This worked for me on my stubborn cell phone when all the other fixes failed.
Once you have the cell phone's head phone jack cleaned and lubricated, it is also a good idea to use some rubbing alcohol to clean the headphone plug, in case it has any sticky residue on it. In my case, I had gotten some salt water and sand from the beach on my headphones which eventually caused the cell phone headphone jack to get stuck in "headset" mode.