Cell Phone -- What remains wet?

I would wash it in distilled water. There are mineral deposits in fresh unfiltered water. Minerals are even added to purified water for a better taste. These minerals are conductive and even more so at the minute scale of circuitry in a cell phone. At this point you don't have much to lose by giving this a try. I have done this for a Motorola text pager that fell in a glass of beer :)

Actually, de-ionized water isn't de-ionized. It actually has "hard" ions replaced with "soft" ions.

I'm old enough to remember the Wantz "Kleensteam" ion-exchage-resin column to make soft water for steam irons.

If it is a different battery, maybe the different battery is not as good as the original battery, I would take the phone and use alcohol to rinse it out.

Please read what I wrote, and do a little research under "ion-exchange" columns. Thank you.

I'm old enough to remember my mum using the melt water from defrosting the fridge.

Gareth.

I spent a combined effort of several hours first trying to dry the phone. I did that successfully before, not this time. Although dring it under a lamp and also using a desicant improved it greatly. I finally had the phone apart several times carefully cleaning, scraping, and also using some Bullfrog contact cleaner. After a week the phone seemed to go into a mode and say the battery was low, but would sometimes come back without shutting down. After a longer period the owner now reports its OK. ??

greg

Thanks to all who have contributed to this thread. I have benefited from all of the remarks. I must admit I wasn't thinking of residual mineral or other type of deposits. When dry I thought that these would be in the order of megohms and since the cell phone works at such a low voltage, they would not matter.

Everything that I had around, distilled water and alcohol, had measurable conductivity. I even measured some vodka. It too had measurable conductivity, but after properly disposing of it, I didn't care as much. So today I bought some Electronic Cleaner at my local Radio Shack. It comes with a brush to clean the printed circuit board. By tomorrow I should know whether I accomplished anything.

Thanks to all again, Dan

LOL!!

In general, the first rule with any kind of liquid damage, is get the battery out as fast as possible. I have on many occasions seen the results of electrolytic action across close spaced tracks and component legs, as a result of small currents passing through the liquid that is doing the contaminating. This often leaves a conductive 'corrosion' mess behind it, that can be quite difficult to remove, and tends to leave component legs and solder joints, a dull grey. Solder thus affected, is very difficult to reflow. Thru' plated holes can also be attacked, and if it gets that far, you are in trouble ... The areas usually worst affected, are those where the voltages and current availabilities, are highest i.e. around the power supply, so that may well go along with your apparent battery discharge problems.

The second most important rule with liquid damage, is to get the item into a warm dry place as soon as possible, for at least 24 hours, before putting the battery back in. In the UK, that usually means the airing cupboard, where the household hot water storage cylinder is located. I've no idea whether houses in other countries have a similar cupboard, where bed linen is kept, for instance.

Following these two 'rules', will often result in full recovery of the item, with no ongoing problems.

Arfa

Well, it also operates at _MEGA_ cycles -- where all sort of 'stuff' matters.

As I said previously, the phone operates perfectly except for a more rapid discharge of the battery even when it is turned OFF. Of course, I have no idea what circuits are active under these circumstances to detect a request to turn the phone ON. If this is a small computer chip of some sort, I can see that you may be talking about Megacycles. That seems like overkill for a simple turn-on circuit, but I without a schematic diagram, I have no idea.

Dan

Thank you Arfa for an explanation of the possible mechanism involved in the creation of a conductive "corrosion" mess which may have remained even after I dried the cell phone out. The phone was in about six feet of water for about 15 minutes. It was not ON, but the battery was in place and I suspect that corrosive paths were established during that period of time. I don't remember enough electrochemistry to know exactly what was happening, but the lake water which I measured today does have measurable conductivity. It's actually about half the conductivity of my tap water which comes from a well so I guess I was better off dropping it in the lake than dropping it in my sink. :-)

Dan

Hi Dan. The alcohol must be pure alcohol and not contain any water. Pure alcohol is not easy to get. Years ago at my place of employment we hsd some electronic equipment that had gone under water in a flood and what got the water out was pure alcohol which I believe has a great affinity for water.

Had to get a clearance from the Customs and Excise people before getting a large bottle from a chemical supply company. The pure alcohol is very volatile and should be used very carefully, no smoking

Lionel L Sharp

"William Sommerwerck" wrote in news:A9adnazyNts7IcTVnZ2dnUVZ snipped-for-privacy@comcast.com:

You are thinking of water softener columns. They replace hard ions with soft ones.

Deionized water's quality is measured by checking the electrical conductivity of the water.

Deionized water has low conductivity.

In a de-ionizer, the ion exchange resin replaces Ca++, K+, Na+, etc with H+ The ion exchange resin replaces SO2--, CO3--, etc with OH-

De ionized water thus has low conductivity.

Softened water, on the other hand, is still conductive.

"William Sommerwerck" wrote in news:A9adnazyNts7IcTVnZ2dnUVZ snipped-for-privacy@comcast.com:

You are thinking of water softener columns. They replace hard ions with soft ones.

Deionized water has low conductivity.

I have now gone through a second cleaning with the Radio Shack Electronics Cleaner. On the first round, I sprayed, lightly brushed, and sprayed again, and didn't really notice any discernable change in the rate of discharge. I guess I envisioned that the solution would dissolve the contaminated residue without a great deal of brushing.

On the second round, I sprayed, more vigorously brushed, and sprayed again. After this I did see an improvement. It is probably not 100% cured, but I think that I am going to live with it as is. I'm afraid that during one of these sessions, I may create another problem that I didn't have before. In addition, perhaps the remaining conductive residues will dissipate with time. Yeh right --- well it's nice to have hope.

Again, thanks to all.

Dan

If you apply pure alcohol to something, here comes the water.

Water is best for disolving green stuff on terminals or traces. I have seen other colored material some times. My usual procedure for nasty equipment, water, alcohol, warm air blowing, sometimes add WD-40 or CRC 2-26, more blowing and drying.

greg

This is a postscript to my previous messages. In an effort to clearly determine whether a continued wetness or a corrosive residue was the problem in my cell phone's behavior, I conducted an experiment which seems to rule out a corrosive residue on the surface of the board.

I cut out a small section of a circuit board which had two adjacent traces and measured the resistance between them. It measured as an open circuit on a meter that can measure tens of megohms. I then immersed the circuit board in water which I took from the lake in which my cell phone had spent about 15 minutes of time. The resistance measured between 22K to 28K Ohms. I then applied 3.7 volts to the terminals of the circuit board for 15 minutes. Immeditaely after removing the voltage, the resistance measured an open circuit but continued to drop rapidly until it reached the previous value in the 20K ohm range. I then dried the circuit board, and in a very short period of time, the measured resistance was again an open circuit. In other words, there did not appear to be any evidence of a corrosive residue on the surface of the board.

I should say that I did not use the same circuit board that is in the cell phone. Perhaps the cell phone board is more porous and retained more of the water with impurities. In addition, I took the water for the experiment from the surface of the lake and not from the bottom, and the cell phone board was subjected to a higher water pressure at a six foot depth. Nevertheless, if I had to guess, I would say that pure alcohol as suggested by some in this thead would probably have done the most good in correcting the condition, and may in fact even improve the present state of the cell phone if I could ever find some. The circuit board may in fact still be wet to a small degree. It does not appear that the problem was a surface corrosive residue produce by the battery voltage being applied to the cell phone during its submersion.

It's not just the water. it's the other stuff that's already on the board. Flux residue, electrolyte leaking out of caps, glues used in the assembly process. Whether or not the final inspector belched on it, Whether the cat peed on or near it. I'm gonna go out on a limb and suggest that water is never the problem. It's what is in the water that causes the grief. Water just ionizes it and makes it mobile.