"USB supplying power to attached device" notification keeps popping up

[Exhotic]

I have the phone for 3 weeks now, the problem started 2 days ago on my trip to sea, the USB notification was there for good at first and wouldn't go away, but now I cant even use the drop down function cause the notification keeps appearing and disappearing every second which is probably wasting my battery as well, it changed from the first stage to the second when i rebooted and tried cleaning the charging port out, looking inside with good lighting I can't see anything inside. 

The cause of the problem is either the fact that i charged it in the car with the gb cars charge port but I did use the sony original cable, or maybe when I was on the beach something got inside the charge port, however as I have mentioned I don't see anything inside od it, any help is appreciated. Thank you. 

[CameronT]

Hi @Exhotic, welcome to the community. I am sorry to hear about this.

It does sound like there may be some moisture in the charging port, though cleaning should fix it if that's the case.

Try starting your phone in safe mode and see if it does the same thing.

If not, it will be an app problem.

If it does the same thing, run a software repair using Xperia Companion. 

If the software repair does not resolve the issue, then contact  your Local support team as it will be an issue with the charging port.

[Exhotic]

Okay so I've encountered another problem when I can't charge the phone I have to reset it, but I don't mean just power off and then on again. Cause if I power it off it won't power on again it just vibrates and does nothing so then I have to use the volume up and power key together to turn it back on. 

I've run a software repair with xperia companion but the problem is still there and the message "USB supplying power blabla" is still there and I still can't charge, I can keep trying to clean the charge port but nothing seems to help. 

[CameronT]

@Exhotic,

I am sorry to hear none of the other steps have resolved this for you. I recommend you contact your Local support team to arrange an assessment.