A customer brought in a laptop the other day stating it had water damage. She turned it on afterwards and found that the keyboard was not working correctly, some keys didn’t work on one side.
If this happens to you I recommend NOT turning it on at all, even removing the battery. The entire laptop should be taken apart and assessed for damage, which is what I did in this case. In the end the physical damage was limited to the keyboard, which I replaced.
It could have been much worse. The possibility that other components get damaged from water is rather high, since there are venting holes all around the laptop which dissipate heat. Any place air can get in or out, water generally can as well. The hard drive is the most important component, since that is where your data resides. If you do not have a backup, you will lose all your files.
So if this happens to your laptop, don’t panic. Dry it off the best you can, and call me immediately.