My computer keeps turning off and restarting- help please

I spilled water on my computer last week. I tested the psu using a YouTube tutorial to see if it was still good and it past the test. I was unable to turn it on by the power button but was able using the psu switch. However, it kept turning off after one second when I turn the psu switch on.

I changed the motherboard, and it came on, but kept restarting with a blue screen. I know blue screen sometimes mean hard drive is not working, so I took out my memory cards ( one by one) still no good. I took the video card out too.

Worse part about it now is nothing is showing up on the monitor now.... I don't know what to do. Can anyone help me?