Today we have a new patient in the lab: a Galaxy Nexus phone that took a dunk in a river. It has been dried right after that and continued to function for a good six months after until it finally died. The only thing that happens when power is turned on is you get a short but blinding flash of camera LED and then everything goes dead. Time to take it apart and see what we can do. There isn’t much hope or a component level repairs on something this dense, but we’ll never know if we don’t try. I won’t bore you with the details of taking it apart- it’s been documented countless number of times on the web. Basically take the back cover off, remove battery and SIM card (this is a Verizon version, so card gets in the way) and remove 6 screws. After that it’s all prying and pulling. Plastic case tools or a guitar pick come handy.
Once the case is open, there is one more screw holding the bottom speaker/antenna assembly. After that it all comes apart fairly easy, just need to unplug a variety of flex cables.
Water damage is pretty obvious- all immersion indicators went from red to clear on the battery and the speaker assembly. There is also plenty of white corrosion powder all over the boards, in some cases bridging across pins or smaller parts or even between parts and shields.
There is white residue even on the metal frame of the unit -pretty bad. First step is to try cleaning it off with some regular rubbing alcohol and brushing. That did not seem to help much, so it was time to bring out heavy guns (err bottles). A 91% alcohol and full immersion shoud do the trick:
I found a suitable plastic tray from an LCD panel, poured enough 91% rubbing alcohol to cover the board and left it there for a few hours, Then I literally brushed it with a toothbrush while submersed. Finally, a rinse in a clean batch of alcohol and things were left alone for a night. Next day inspection showed no signs of corrosion anywhere on the board. Note that only main board was washed. I did not feel like trying to wash camera or speaker modules. Put the board back in, connected power and we have a Google logo on the screen. Put the whole thing together, press power, volume up and down, and the bootloader screen is on in its full glory. And no pesky Flash LED on power up either!
The phone now operates completely normally, with no visible problems. At this stage I can only speculate what the corrosion was doing to the circuits and how conductive it was, but the fact remains that a scrub in alcohol has restored things to normal function.