1. Do not try to turn on the device, or plug it in to charge or back it up to a computer. Doing so can send electricity to circuit pathways surrounded by water and cause more damage.
2. Do not put the wet device in rice or any other desiccants as doing so accomplishes little and wastes valuable time. Time is not your friend once the phone hits the water. Do not waste it!
3. As soon as possible, remove the battery. On some phones, this is relatively easy, others, not so much. If you don’t have the tools to remove the battery, get it to someone who can right away.
From here on out, specialized tools and equipment will be needed.
4. Remove the phone’s logic board and if any cameras are attached to the board, remove those too. You will be running the logic board through an ultrasonic cleaner and you do not put cameras, batteries, or phone screens in the cleaner.
5. Remove any shields covering tiny SMD components on the board. As a word of warning, this is not easy for someone without soldering experience, especially with hot air and it is easy for the inexperienced person to de-solder and blow tiny SMD components off the board and not know it. A microscope is recommended for board inspection. If the phone was damaged in a sticky or very dirty liquid, soak and rinse the board in distilled water and/or isopropyl alcohol first, otherwise you will end up cooking sugar and who knows what else when you try to remove the shields.
6. Place phone’s logic board in an ultrasonic cleaner (preferably one with a ‘sweep’ feature and accurate temperature controls), and filled with only distilled water and a cleaning agent meant for electronics (like Branson EC). Run board through the cleaner for 4 cycles at 2-3 minutes each, changing the position of the board with each cycle (flat on both sides and vertical or diagonal in both possibilities). So, lay the board like this _ and then flip it over for cycle two. Then like this / for cycle three and \ for cycle four, or stand it vertically, then flip it 180 degrees for three and four. It doesn’t really matter what position the board is in as long as you’re changing the position for each cycle.
7. Rinse board in distilled water to remove the cleaning chemicals. As an extra step, once the board is rinsed in distilled water, you can rinse it in isopropyl alcohol to displace the water and speed up drying since alcohol evaporates faster and at lower temperatures than water.
8. Set a hot plate to 65 degrees Celsius. It’s good practice to put a silicone baking mat on the hot plate to prevent scratching device screens when heating them for removal or to heat new adhesive to cure a newly placed screen. If you use a silicone mat, put the logic board on it rather than the plate directly. However, the board can sit on the plate’s surface without issue. Leave the board for at least 10 minutes, then flip it over and leave it for another 10 minutes. Water (or the alcohol rinse) can leach underneath some of the BGA components and other tiny spaces, so it’s important that you dry the board completely.
9. If you have a microscope, inspect the board for damage or remaining corrosion. You may find that some connections and solder joints have been damaged by corrosion. If you know what damaged solder joints look like and have the ability to touch-up or re-flow these areas, you should. If additional corrosion is found, a soft toothbrush and some alcohol can be used to gently brush the area. A fiberglass scratch pen works well too. Re-rinse the board to remove any flux if you’ve soldered, brushed off corrosion, or fiberglass fibers, then repeat #8.
10. Once you’re sure the board is dry, reassemble the phone and test. It is ideal to maintain a device frame with known-good components (buttons, charge dock, and battery) installed in it to test cleaned logic boards since the original components were also wet, and may be damaged or corroded, causing less than ideal testing conditions. If you don’t have new components or a dedicated testing frame, then inspect the original component connectors for corrosion and if any is found, clean them with a soft toothbrush and alcohol or a fiberglass scratch pen.
11. When testing, it’s only necessary to connect the LCD and digitizer, the battery, and the dock connector. However, you can also connect the cameras, buttons, and antennas if you want. Try to power the device on. If it doesn’t turn on, try plugging in a charge cord to bypass the power button since most devices power on when plugged in. If it still doesn’t turn on, wait for 30 seconds to a minute and then inspect the screen under a bright light to look for any images. Sometimes, as a result of water damage, the LCD backlight fails and the device still powers on and functions as normal, but because the LCD is dark, many people assume the device is dead when testing of the backlight circuit is needed to find a burned out filter, diode, or other component. If you can see an image under a bright light, you have a backlight problem. If the screen is still black, you have other problems. In either case, for most people, this is as far as you can go and you should stop here. If you have testing equipment (multimeter, oscilloscope, etc), can read a schematic , have a good understanding of electricity and electrical components, a microscope, and some good re-work soldering equipment (soldering pencil, hot tweezers, pre-heater, hot air wand with pressure control, BGA station, etc), then it’s time to start testing circuits and finding the cause of device failure. At this point, often, saving the device exceeds its value and should only be done to preserve data (ie, photos, contacts, and other unsaved information).
From start to the testing phase, if you’re spending more than two hours, you’re taking too long. Do not sit idle while the ultrasonic cleaner is running, or the board is drying. If you’re multi-tasking while restoring wet phones, you’ll get more done. If I get to a point where I can’t do anything else (8-12 minutes of ultrasonic cleaning, 20 minutes of drying, etc), then I start on the next phone. It’s not uncommon for me to be working on 3-4 devices at a time. Organization and multiple magnetic work mats is a MUST here, otherwise, you will end up mixing parts and phones.