USB and Water Pump

[BLtravels]

Still trying to dial in the new/used TT. Trying to use the charging station I found the USB plugs do not work yet the 12 volt does. Checked the back and everything is wired and plugged in. Any ideas?
Is it normal to hear a low hum when the water pump is turned on but no faucets are open? I am not referring to the very obvious noise when water is turned on but a very low hum just by being on. The water level was pretty low when this happened.

Thanks as usual

[Papa-T]

If you don’t have enough water in the holding tank for the water pump to pick up water it will just hum. And can burn out your pump. As far as the USB it will work on batteries so not sure there. Are your batteries charged? Had a friend that had one that stopped working. He ordered another one on amazon and it worked fine when he wired it up. Could just be a bad one that stopped working.

[RoadRat]

Are the USB plugs part of a wall outlet? If yes, they may need 120v.

[Papa-T]

True, mine is on my radio so it works of 12v, but if on outlet, shore power would be needed I would think.

[Steve7]

My water heater will give a low hum when warming on electric. When water is hot it stops humming.

[BLtravels]

I am fully charged and plugged in. Maybe a replacement is needed but it looks specific to that charging station. Possibly a generic one will fit. I am assuming since the 12 volt is right next to it and working that it might be powered by the 12 V system.