First, remove and clean the logic board using 95%+ isopropyl (if there is any visible liquid on the board).
After this has dried, reassemble and try turning it on. If it doesn't boot, try plugging in the charger without the keyboard connected, since this can prevent booting. If it is still not working, try plugging the charger in without anything (except the essentials, fan, charger port, etc) plugged in. If it is still not working, the fault will be with the logic board.
Replacement boards are expensive, so take it to someone to repair if this is the case (or repair it yourself, if you have the equipment).
EDIT: Good it's all working. The issue will be related to the battery if it is only working on charge, and it had corrosion on the battery PCB.
You need to use a large flat tool (painting knife for example), dip it in isopropyl, and slide it under the battery carefully, to loosen it. You will need to remove the board and speakers to get the angle, and do not accidentally cut the trackpad cable or keyboard cable. If you are not confident in being able to do this safely, either live with the issue or send it to a repair company.
Also, be careful not to puncture the battery, bad things will happen D: