When I plug my USB lead it shows as a small notification at the bottom of the notification panel and theres no sound or no pop up.
If you expand it and swipe slowly to view the cog icon, click on that to adjust the notification settings, you could change it to high or urgent priority and next time you plug in your cable it will show a notification. Have a look at the screenshots.
If you expand it and swipe slowly to view the cog icon, click on that to adjust the notification settings, you could change it to high or urgent priority and next time you plug in your cable it will show a notification. Have a look at the screenshots.