Dead power button - Can it be fixed with a new keyboard?

I have a late MBP 2011. There was a little bit of water spill on my keyboard. As a result, my power button is dead but all my other keys are fine. Because my power button is dead, I just put my computer on sleep mode because I can't turn it back on if it's shut down. But, if I really need to power it up, I have to open the bottom case, unplug the battery, and plug it back in again to get it to power up again.

Now, I am thinking of repairing my keyboard myself by buying a keyboard from somewhere and installing it. But, I was wondering... why that fix the problem? Because I am not sure if 1) the power button on the keyboard is dead or 2) (I am not sure if this might could be an actual problem ) could it have fried a piece of the logic board that controls the power switch. Is there a way to find out?

If the problem is 2) a piece of the logic board is fried, does this mean even if I replace the keyboard with a new one, I still can't fix the power button?

Thanks