What Causes a Wet Phone to Short Circuit and Can it be Repaired?

[Butters]

There is a lot of info on how to save a wet phone and mine is now sitting in a pile of rice. Anyway, I'd like to know what physically happens to a phone exposed to water. Short circuit would be a short answer but why should it kill the phone irreparably? Is it possible to get some use of it afterwards?

 

[chrisbaird]

A short circuit sends more current than expected to parts of the circuit, causing them to physically burn out as they are not designed to handle such a load. If you opened up the phone, you may even see burn marks and melted plastic on the circuit board. Replacing the burned out circuit components can get a device working again, but these days it's usually cheaper to just get a new device.

 

[Butters]

So basically, the amount of time that a device is exposed to water does not really matter because it doesn't take much for the short circuit to take place. So the question really is, can I save the a phone which has experienced the short circuit?

 

[Averagesupernova]

Rice has saved a number of phones. I think the main damage comes from corrosion. If a copper conductor conducts into water pretty soon there is no copper left. If you pull the battery as quickly as you can after exposure you will prevent this. The rice I would assume just absorbs all the moisture out of the phone.

 

[Butters]

I see. Didn't know that corrosion may take place so soon. Too bad my phone was submerged for way too long and I have seen phones killed in seconds. I guess I'll update with the results after 20 hours.

 

[meBigGuy]

My ipod touch went through a full washer cycle. When I sadly retreived it I did not try to turn it on. I put it in rice for a month (luckily I didn't really need it). When I turned it on, it worked perfectly, including the wifi. I think the most important point is to not turn it on while it is wet. If you were lucky it might have powered down before it damaged itself and might be OK once it is dried out.

 

[skeptic2]

I used to work in quality where I tested products after accelerated life testing. One of the tests exposed the circuits to high humidity. When a unit failed, we checked the circuit board under a microscope for dendrites. These are tiny metallic threads that grow between oppositely charged traces and are too thin to be seen without a microscope. This was a common occurrence.

They grow rapidly enough to be seen growing under the microscope. Sometimes when we couldn't find the dendrite we'd scrape between traces of opposite polarity and usually the problem disappeared. Note: the device does not have to be turned on for this to happen. Battery traces and the on/off button have a voltage gradient between them even when turned off. These dendrites persist even after the unit has dried out completely.

 

[Butters]

I used to work in quality where I tested products after accelerated life testing. One of the tests exposed the circuits to high humidity. When a unit failed, we checked the circuit board under a microscope for dendrites. These are tiny metallic threads that grow between oppositely charged traces and are too thin to be seen without a microscope. This was a common occurrence.

They grow rapidly enough to be seen growing under the microscope. Sometimes when we couldn't find the dendrite we'd scrape between traces of opposite polarity and usually the problem disappeared. Note: the device does not have to be turned on for this to happen. Battery traces and the on/off button have a voltage gradient between them even when turned off. These dendrites persist even after the unit has dried out completely.

Should I be concerned about those dendrites? I read that they cause short circuits though I don't know If I have them and how to deal with them.

 

[the_emi_guy]

I was handed a cell phone that had been left out all night in a thunderstorm. It was full of water, even visible behind the LCD.

Removed the battery.

Next put it (and the battery) for 24 hours in an environmental chamber set for 100 degrees F, 0 percent humidity. This dried it out.

Next I opened it. There was noticeable corrosion on the PCB in the area where the battery connects.
Cleaned it with Proclean and Q-tips.

Closed back up and worked fine.

 

[skeptic2]

Generally dendrites between battery traces don't survive because of the current is enough to burn them open, they will often survive between traces with higher impedance. I'm writing this on a laptop on which a few drops of rainwater from a leak in the roof landed a week ago. Everything works except the two mousepad buttons. I'm debating whether I should take it apart and try to find the dendrites or what.

 

[Butters]

The screen is shimmering (flickering) and a bit dim now. Everything else looks fine, even the battery didn't drain a bit after the accident. What should i do?