PSU makes a constant noise then PC is off

As i stated, my PSU makes a constant low humming noise when my PC is shutdown. It started when I spilled water on the surge protector and knocked out a trip switch in the house. Some water got into the PC also, but it was dried thoroughly befire I turned it on again. I cant really remember how I spilled the water or where exactly the water went, because I was rotten drunk at the time.

The problem starts when I turn off the switch to cut all power to the PSU so that the humming stops at night. But sometimes when I turn the PC back on, i have to change boot drive in the setup screen and the clock when windows loads. Also, my icons on the taskbar are hidden but they come back when I restart. Also, website like gmail dont have certificates when I visit them so I get a warning that this site may harm your computer. It seems something isnt saved when I cut the power. Is it the battery on the motherboard or what?

Can someone help me out?

Its a thermaltake 600w PSU with an Asus P5K3 Deluxe motherboard.