Water damaged cell phones
My son jumped into a swimming pool with his Sprint m620 (Upstage) in his pocket. I tried letting it dry for two days but it appeared dead and wouldn't react to anything including plugging into a charger. I took it (covered by a service and insurance plan) to a Sprint "Super" store and a tech said that it was a sealed unit and all I could do was to pay the $50 dollars to Asurion and have another delivered. Upon further discussion he admitted to being able to carefully pry open the bottom exposing the battery and suggested that might help it dry out. Well that didn't help so using my experience cracking open several cams, I kept gently prying and managed to take both the front and back cover completely off, remove the battery and disconnect the keyboard. Surprisingly it then came on when I plugged in the charger, but obviously without a keyboard couldn't do anything else. So I put it all back together and the flip side without a keyboard works fine but several keys on the keyboard don't work including the power on key - forced to power on by a quick temporary charge connection. Also although speaker rings (musical notes) and I can answer, there is no sound coming from the caller's phone and the microphone seems dead. I also managed to dump his phone book using Sprint's backup service ($2 a month with no Sprint option to directly download phone book through their usb cable and software - a disgusting ripoff). I doubt it is worth much more effort but I am open to any suggestions. There appears to be quite a bit of sediment (salt, chlorine ...) and I wondered if there is a way to spray/wash/clean the pcb.

you can always try soaking it in rubbing alcohol then allowing it to dry. I've had a few things spring back to life after a bath in rubbing alcohol.

If you have access to an ultrasonic cleaner, run it through three cycles with fresh distilled water each time. Otherwise just rinse several times. Shake out as much water as you can. If you have it apart blow off as much water as you can with canned air. Then let dry. Overnight in an oven on LOW (some ovens you may need to open the door and place the device somewhere on the door that is not too hot... 50 C is safe), in a hot car, etc works well.

The hot car dashboard is a good way to loosen up m220/230 lenses from their goopage, also.

The main problem with alcohol baths is that it can fog up plastic display windows. If you can remove the circuit board from the case, alcohol is usually OK.

I removed everything from the case one too many time (Samsung m620 upstage has two lcds). But on the last try I completely tore the thin ribbon going to the keyboard which appeared to be glued to the case and very well sealed with no apparent water having crept under the sticky sheet covering the contacts. The phone was working fine but some of the keys weren't including the end/power key. I suspect that the ribbon was slightly torn after I first opened the case since the keys that didn't work were all in the same column. Any suggestions on how to repair a very thin ribbon cable that has been completely torn apart? I can match the two ends - and wondered if the heat from a soldering iron might melt the plastic allowing the flat metal lines to contact each other.

you can replace each strand of the ribbon with a length of 30AWG wire

I'm waiting for this treatment to be commonplace: http://golden-shellback.com/ Rarely can an untreated cellphone be brought back from the dreaded dump. If it falls in the toilet, might just as well leave it there.

A great way of fixing it but unreliablebly is to dunk the entire system into distilled water at room temp(around 75) let dry, dunk again in fresh distilled water, and repeat once more. This will help to remove sediment and other particulate. Others say to use rubbing alcohol but this will ruin sensitive equipment like a transmitter or microphone or speaker. If you want use a 5 parts water 1 part 20% rubbing alcohol mix. The next step is tedious but VERY important. Letting the water dry can cause white junk to build up around motherboards which will cause shorts. Using a toothpick or finely sharpened tool remove as much junk as possible. Now the final step, take rice(not instant rice) and put a half-inch or so layer at the bottom of a tupperware container and put a part in layer with a half inch of rice and continue until all components are covered with rice. It might not be a bad idea to make sure that rice does not conduct electricity when dry or wet, if so, get different rice. Let sit in the sun for at least a week. Next remove the components and shake vigorously until all rice is removed. Reassemble and hopefully it'll work.

Actually isopropyl alcohol is a VERY common cleaner used in PCB manufacturing. My old company used tons of it. Most electronic components are washable in either water or alcohol. Occasionally you might find an item like a dip switch or relay that is not washable (mainly because the solvent can carry contaminants into the device).