What would be most likely is that the water would produce short circuits
that would cause transistors and diodes to pass excessive current and fail,
and/or damage traces on the board(s).
Now for the bad news: Most of the transistors in today's TVs are inside ICs.
The most efficient method of repair involves determining which circuit board contains the bad parts
and replacing that entire board.
Very few boards in today's TVs can be readily serviced because the parts are so small.
Replacing individual "chip" (surface mount) parts such as resistors, capacitors,
diodes, and the few transistors that aren't buried inside ICs
takes great skill with a very small soldering iron, thin solder, a magnifier, and steady hands.
In other words, nice idea, but it would be more valuable to practice on older, cheap radios
and audio components that won't be worth much even after you get them working.
Things with "through hole" component mounting will give you lots of opportunities for easy soldering.
After you have acquired the requisite basic knowledge and skills that way,
you might be better able to repair more modern stuff.