Keyboard keeps typing a character

Sometime ago I spill water on my keyboard, on the area of character '1'. And ever since the key '1' keeps typing himself when unneeded.
After the splitting I detached the keyboard and dried it, I cleaned it several times after it too. When nothing helped I even switched to a brand new keyboard, but even this didn't help.
So if the problem not in the keyboard, where it can be? Maybe it's the old connections of the keyboard and laptop? Maybe the connection is a little wrong? Or on what another levels the problem might be..

Guys I'll be grateful for answers and advices, really want t solve this problem