May have gone into a 'hibernation' mode. The key marked "Fn" plus one of the "F" keys should bring it back to life, if still viable. Check for a user's guide on the model to get the use of those keys with different color markings that are combined with the "Fn" key.
Laptop batteries have a thermal safety fuse in their case. If it melts, then there would be no output on its terminals. You can check with a 12 volt lamp that draws around 1 amp of current, to see if the battery is good.
The terminals on the battery should be noted as (+) and (-). A third or fourth terminal would be a heat sensor lead. But no need of polarity concerns, with a small lamp. Just that the main terminals are used.
If the keypad did get any liquids into it, try disconnecting it to see if the unit powers up. Doubtful by using an external PS2 or USB keyboard would it cause life signs to show again, if the keypad is shorted.
F@H.. to solve mankind's maladies.. in our lifetimes!