I wonder that why headset icon not coming in notification bar in Galaxy s3 when I placed headset jack into the phone. I search many forums regarding this problem of Galaxy S3 and many other galaxy devices and found the solution of this that I am sharing in this post. First of all one thing is clear that headset icon only works when you have selected default launcher as Touchwiz , if you have installed any other launcher and selected as default the headset icon will not be shown more in notification bar.
The other thing is that in settings >display>page buddy , if you have not selected earphone page than you will not be able to get earphone page turned on, also icon will not shown in notification bar.
There are two solution for this problem either you always been selected default launcher as Touchwiz and earphone page checked under pagebuddy setting. The second solution is that install any thirdparty app from Google play like Headset Icon to turn on headset icon in notification bar.
Actually this is a bug that not solved by Samsung in their devices, Samsung is responsible for this bug.