Micro won't work after boiling water under it all day

No! the keyboard was already failing, But I'am more concerned the keypad control board is the issue and one of the most expensive pieces.

A Microwave Oven works by heating water/moisture in food: if the boiling action (e.g. when boiling water) is greater than the oven exhaust fan can cope with, then the inside will steam up and fog the door glass: this is usually OK and 'normal' (this is actual the advise in cleaning up the interior of a microwave oven - steamy soapy water - see your manual).

Hope it helps.

How about boiling a small container of water and once it starts boiling. Just shut the unit off and let it sit and let the steam do the work for you. Might soften it enough to scrape it off.

Re: GE JES1384SF Mine quit working so I unplugged it and put a pot of boiling water in it and let the steam dissolve whatever was gumming things up. I used an electric hot plate to keep the water boiling. I let it boil for a couple of hours. I left the door 2/3 open. The microwave is working again. It is four years old and has been used every day, many times a day before it stopped working.

Here is a simple power test.
Place a measured cup of water into the microwave. Run the micro for 2 minutes. A 1000 watt micro will boil a cup of water in 2 min. Check the power output of your machine. It will be found on the model number tag. A 700 watt micro will take about 3 minutes. If this occurs, the machine is working properly.
Otherwise, check the outlet voltage, should be 110 or higher.
Outside of this, you could need a high voltage capacitor or magnetron.

you vent fan motor may be trying to vent upwards instead of towards tthe front of the unit, you may need to rotate motor

One would think that you would have the sense to use the extractor that is above your stove and under your microwave, would you use a laptop in a sauna!!! no wonder the thing is shorting out. Contact the person who fitted the microwave. always use the extractor when you boil things on the hob.
I live in England it is illegal to have a microwave above a hob for this exact reason. America will catch up eventually with building regulations!!

I would guess that the boiling water may not have been the cause ...
If you are lucky ... try this first:
Unplug or turn the circuit breaker off (if it is a built in unit). Wait an hour and then repower.
Odds are that will not clear things up ... but it is easy to try. Probably one of the electronic internals broke.
A number of different internal component problems could cause this heating failure in the microwave. It could be the magnetron, the high voltage transformer, the PC board, the diode, and the capacitor. This type of problem will need to be diagnosed and repaired by a service technician. Microwaves are inherently dangerous to service. This type of repair is not something that you want to try to do yourself. Internal capacitors in the microwave can retain a lethal electrical charge even when the microwave is completely unplugged. A microwave radiation leakage test should be performed on the unit using proper testing equipment following any internal component repair.

I wouldn't recommend to use the microwave to boil water. Here you can read the reason why: http://www.snopes.com/science/microwave.asp

Water can 'explode' when heated in a microwave under certain conditions. Best way to boil water should either be using a water boiler or an old-fashioned kettle.

door micro switch open/need to replace / if that open the magnetron will not power no heat will produce.