Re: HTC ONE not charging and Usb not recognizing !
I had same problem, not charging, random car mode, orientation switch, speaker phone on and off, usb host cable plugged in notification. I tried most of the methods mentioned in this thread, safe mode, cleaning (DRY toothbrush), turn on and off fastboot, hard and soft reboots, htc dialer code for testing phone. none of it worked.
took it into sprint and they found a very small amount of corrosion on the contacts of the usb port and that was enough to void my warranty and want to cost me 150 to replace. Did not even check the water sensors on the inside.
I was just now fiddling with the usb cable and phone wiggling it and putting pressure on different spots so the contacts would scrape the connectors in the phone and it just started working, Not sure if this is a permanent fix but it reinforces the notion that this is a dirty connector problem. The only thing i was doing was messing with the cable for 5 min and it started working.
Just rebooted to test if it was permanent but to my dismay it was charging, messed with the cable a few times and got it working again.
Remember to clean all your ports before going to see sprint even if you don't think that is the problem, Now i have a void warranty with a working phone(for now). I will try and go get the warranty reinstated but the shop around my area is not know for being generous.
hope this helped