Hey, i got this problem, the headphone logo is on my htchero, but there is not headphone plug in, therefore i got no sound unless i plug in my headphone, but when i take it out, the logo is still there. to make it worst, i now cannot sync to upgrade the software. i did a master reset, and the headphone logo is still active. Please anybody has the same problem help me out. All i did was switch off my phone and turn it back on, this happen.