Using desiccants to soak up wet electronics
Water damage is one of the more common threats to portable electronics, but sometimes if you dry them out properly, you can restore your otherwise broken device.
One of the most common and damaging threats that portable electronics face is exposure to water and other liquids. Dropping an iPhone or iPod into a pool, or spilling a glass of water or coffee on a laptop is a sure way to render the device useless in a heartbeat.
Water damage is unfortunately not covered under many basic warranties, and in many of its devices Apple places liquid sensors to determine if a device has been exposed to water or other fluids if it's being serviced. As a result, many times if you've dunked or doused your device, it may be an immediate sign that you'll be shelling out some cash for a new one, but not always.
When liquids come in contact with the circuits, the currents can be inadvertently diverted (shorted) to other system components where there can be two possible routes: a burnout, or a grounding. When a burnout happens, a higher-current circuit (such as that from a power-handling circuit) is allowed to go through a more delicate circuit that was not designed for high currents, resulting in the circuit components overheating and melting.
When a grounding short happens, the current from a circuit is merely diverted through the liquid to an alternate location that is able to handle the load, such as the computer chassis or one of many grounding circuits on the motherboard and computer components. Shorts that directly ground a circuit have less potential for harming the circuit since the grounding components are built to handle higher current loads.
Liquids have a chance of doing either of these types of shorts, but often when they penetrate a device the components are just grounded instead of burned out. As a result, if you are able to dry your system thoroughly, then you have a chance of clearing the shorts and possibly restoring functionality, especially if the liquid is relatively free of salts that even if dried can form conductive crusts that may continue to short the circuits.
Unfortunately liquids can very quickly be pulled into the tight crevices and small components of circuit boards, aided by a process called "capillary action." Therefore, even if a device appears to be completely dry, there may still be a small amount of liquid left over, and if it shorts just one circuit, then the device may not operate properly.
Water evaporates through its contact with dry air, so to dry liquid fast it is best to have as much of it exposed to air as possible. Try submerging a comb into a bucket of water and then waiting for it to dry. You will see that the teeth will still hold water long after the rest of the comb is dry. In a similar manner, the comblike plugs and connections, and flat surfaces of components that are in close contact with each other will prevent the water's surface area from contacting air, and will thereby retain water between them long after the rest of the device is dry.
One way to clear this liquid out of a device is to open it up and separate all components, and then dry them off with air or absorptive materials; however, this is likely not a feasible option for many devices given the complexity involved in their complete disassembly and subsequent reassembly. Therefore, the other option for clearing out these liquids is to accelerate evaporation, which can be done by both drying out the air around the device as much as possible and by applying heat, and then waiting.
Unfortunately many times people use methods for doing this that either are ineffective or that may damage the device. For instance, technically dried grains such as rice will absorb liquids, so people have used this as an available desiccant to dry out a device. However, rice is relatively ineffective at absorbing liquid from the air and may not be as much help as people think. Additionally, since heat helps water evaporate people have at times baked their devices in ovens or with hair dryers, resulting in melted components and burned circuits (memory circuits such as ROM and RAM are fairly susceptible to damage from overheating).
To help in drying out small devices like iPhones and iPods, the folks at iFixIt have come up with a drying "Thirsty Bag" which is a sealed container that contains the Molecular Sieve desiccant. You can place a drenched phone, camera, or any other device into it and after a while the liquid will absorb into the desiccant and leave the device dry. To help in this process, you can heat the package up a bit using an electric warming pad or similar device, but do not use an oven, as it is very easy to overheat and damage an otherwise restorable the device.
iFixIt's Thirsty Bag is useful, but is sized for smaller devices; however, you can still use it for drying out laptops and other items that will not fit in the bag. To do this for laptops, you will need several additional tools:
- Canned or compressed air.
- Screwdrivers and manuals for opening up the bottom of your laptop (Mac manuals are available at iFixIt)
- A few of iFixIt's Thirsty Bags or another desiccant material like Drierite or Silica Gel.
- A heating pad or other heat source.
- A sealed bag or airtight plastic container that is just large enough to hold your device.
With these tools handy, open the device as much as possible by removing the battery, hard drive, and optionally the RAM. Then unscrew the bottom cover and remove it so the guts of the system are exposed, and then get a soft item like a few wads of toilet paper and use them to wedge the screen open. Then use the canned air to blow in and around the device to rid it of as much liquid as possible.
After this is done, prepare the container by placing the desiccant in the bottom and covering it with some paper towels. If you are using iFixIt's Thirsty Bags, then you can cut or prop them open, and then place them in the container. Then place the laptop and its removed components into the container, propping them up so air can flow around them as much as possible, and seal the container to prevent humid air from entering it.
The last step is to place the container in a warm place, or on the heating pad, and let it stay there for at least a few days. Ensure that the temperature does not exceed the recommended storage temperature for your device (usually somewhere around 100-110 degrees F, though check your device's specifications). Depending on the degree of fluid penetration, you might need to keep the device in there for up to a week to ensure it is fully dry.
When you are ready to try the device again, reassemble it and try powering it on, and with some luck if the only problem was liquid shorting of components, then the device should start right up again.
If the device is still not working anymore and is not covered by any warranty, then a final step you can try is to rinse the device and dry it again. Since it is the salts and other charged contaminants in water that make it conductive, when liquids like soda or juice dry they leave the residual salts behind that can continue to short out a circuit. As a result, you can use pure distilled water (ensure it is distilled and not "mineral" water), to wash the circuits of the device followed by another round of drying it with desiccants. Feel free to liberally dunk the device in copious amounts of pure distilled water so it flows in and around it, followed by draining the device, opening it up, and placing it in the desiccant chamber again to dry.
Doing this should clear out residual salt contaminants left behind from the initial liquid, and potentially clear any shorts they may be causing. Again, only do this as a last resort if an initial drying does not work, and if the device is not covered by any warranties (i.e., you have a dead device you would otherwise just throw out and replace).