Originally Posted by SteveCurrie
Some more info.....
When I connect my OTG cable I get a message 'Phone is in USB host mode'....dont know whether this helps identify what is giving me problems but more info just in case
If you google 'HTC One USB host mode' there does seem to be an issue with some devices. Symptoms include failure to charge with mains charger and failure to connect to PC/Laptop via usb.
The following was apparently a fix for the charging issue but it isn't clear as to whether it fixed the Host mode issue completely.
Others seem to point a finger to 'dirt in usb port/connector'.
It may be worth giving HTC Support a call.