I have been having the same problems with my HTC one - battery won't charge, USB host mode, docking, phone appears to be charging when NOT plugged in, speaker phone goes off by itself and phone randomly goes into car mode. I am on my 4th phone with 5th on the way! Obviously HTC is ignoring these problems because they are rampant and on different models! Don't pay them to "fix" your phone because they obviously don't know what they are doing! Complain LOUDLY! I have been able to get mine to function but problems continue to recur. Unfortunately it takes persistence and what works one time my not work the next. Sometimes I am able to restart the phone. Other times I shut phone off and connect to charger and it will charge while off. Or try pushing power button while holding down both volume buttons for 2 minutes. Then restart. You can do this even when battery is dead. Phone will vibrate and go to HTC screen then off repeatedly. I have tried HTC support which has been no help. Beware that they will try to blame you for the problem! I've been blamed for using wrong charger (the HTC charger died within 6 weeks!), damaging the phone, installing a corrupted app, "this never happens to the same person multiple times" (excuse me! Read the forums-I'm not alone!), etc! We bought 3 of the same model on the same day - only mine has problems. I contend it's because they keep sending me "certified refurbished" phones! Are they really fixing the problems when they won't acknowledge that the problem is theirs??!! Don't pay HTC anything! Go to your provider - verizon has replaced each phone without any charges.