I am attempting to rescue my LG cell phone which spent about 15 minutes in
about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges much
more rapidly even when the cell phone is OFF. This is not the same battery
that was in the lake. Could it be the circuit board itself that is still
wet, and if so, will it ever dry out?

Dan

"Dan Dubosky" wrote in message
...
I am attempting to rescue my LG cell phone which spent about 15 minutes in
about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges much
more rapidly even when the cell phone is OFF. This is not the same battery
that was in the lake. Could it be the circuit board itself that is still
wet, and if so, will it ever dry out?

There is a conductive residue. A thorough washing with de-ionized water is
usually required.

Charles wrote:

"Dan Dubosky" wrote in message
...

I am attempting to rescue my LG cell phone which spent about 15 minutes in
about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges much
more rapidly even when the cell phone is OFF. This is not the same battery
that was in the lake. Could it be the circuit board itself that is still
wet, and if so, will it ever dry out?


There is a conductive residue. A thorough washing with de-ionized water is
usually required. ^
|
|
disassembly and proper PCB

Michael

"msg" wrote in message
ernet...
Charles wrote:

"Dan Dubosky" wrote in message
...

I am attempting to rescue my LG cell phone which spent about 15 minutes
in about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges
much more rapidly even when the cell phone is OFF. This is not the same
battery that was in the lake. Could it be the circuit board itself that
is still wet, and if so, will it ever dry out?


There is a conductive residue. A thorough washing with de-ionized water
is usually required. ^
|
|
disassembly and proper PCB

He said he took it apart ...

There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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.

"William Sommerwerck" wrote in message
. ..
There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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

Uncharged organic molecules, viruses, or bacteria left behind (after
deionization) will not drain the cell-phone battery.

On Jun 18, 6:42*pm, "Charles" wrote:
"William Sommerwerck" wrote in message

. ..

There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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

Uncharged organic molecules, viruses, or bacteria left behind (after
deionization) will not drain the cell-phone battery.

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.

"William Sommerwerck" wrote in message
. ..

There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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

Uncharged organic molecules, viruses, or bacteria left behind (after
deionization) will not drain the cell-phone battery.

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

"William Sommerwerck" wrote in message
. ..
There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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.




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



Gareth.

In article , "Dan Dubosky" wrote:
I am attempting to rescue my LG cell phone which spent about 15 minutes in
about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges much
more rapidly even when the cell phone is OFF. This is not the same battery
that was in the lake. Could it be the circuit board itself that is still
wet, and if so, will it ever dry out?

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

"GregS" wrote in message
...
In article , "Dan Dubosky"
wrote:
I am attempting to rescue my LG cell phone which spent about 15 minutes in
about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges
much
more rapidly even when the cell phone is OFF. This is not the same
battery
that was in the lake. Could it be the circuit board itself that is still
wet, and if so, will it ever dry out?

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

On Thu, 19 Jun 2008 16:25:45 -0400, Dan Dubosky wrote:


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.


LOL!!

"Dan Dubosky" wrote in message
...
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


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

On Thu, 19 Jun 2008 16:25:45 -0400, Dan Dubosky wrote:

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.

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

"Allodoxaphobia" wrote in message
...
On Thu, 19 Jun 2008 16:25:45 -0400, Dan Dubosky wrote:

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.

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

"Arfa Daily" wrote in message
...

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.

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

propman wrote:
On Thu, 19 Jun 2008 16:25:45 -0400, Dan Dubosky wrote:



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.



LOL!!

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
:

"William Sommerwerck" wrote in message
. ..

There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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

Uncharged organic molecules, viruses, or bacteria left behind (after
deionization) will not drain the cell-phone battery.

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

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.




--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

"William Sommerwerck" wrote in
:

"William Sommerwerck" wrote in message
. ..

There is a conductive residue. A thorough washing with
de-ionized water is usually required.

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

Uncharged organic molecules, viruses, or bacteria left behind (after
deionization) will not drain the cell-phone battery.

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

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

Deionized water has low conductivity.

http://www.veoliawaterst.com/en/files/?file=960




--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

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

"Dan Dubosky" wrote in message
...
I am attempting to rescue my LG cell phone which spent about 15 minutes in
about six feet of water in a fresh water lake. I took it apart, dried
everything out, and everything now works except the battery discharges much
more rapidly even when the cell phone is OFF. This is not the same battery
that was in the lake. Could it be the circuit board itself that is still
wet, and if so, will it ever dry out?

Dan

In article , Lionel Sharp wrote:
propman wrote:
On Thu, 19 Jun 2008 16:25:45 -0400, Dan Dubosky wrote:



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.



LOL!!

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

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.

Dan Dubosky wrote:
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.

--
Return address is VALID!
Bunch-O-Stuff Forsale He
http://nm7u.tripod.com/homepage/sale.html

"mike" wrote in message news:tUg8k.29$od.22@trnddc07...
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.

--
Good point, Mike. There may have been something on the cell phone board
that was not on my experimental board. I did however scrub the cell phone
board twice with Radio Shack Electronics Cleaner and I think that there is
still some effects left from the submersion. I only did the experiment
since I thought that some were suggesting that there was some corrosive
residue created by the material in the less than pure water, but they may in
fact have been referring to residue materials of the type that you have
suggested.

On Tue, 24 Jun 2008 21:28:04 -0400 "Dan Dubosky"
wrote:

Good point, Mike. There may have been something on the cell phone board
that was not on my experimental board. I did however scrub the cell phone
board twice with Radio Shack Electronics Cleaner and I think that there is
still some effects left from the submersion.

It sounds like you've been careful and thorough, but your board might
benefit from additional scrubbings in some other solvents, since not
everything is soluble in Radio Shack Electronics Cleaner.

In general, I clean things by starting with clean water, since it is
the most universal solvent. If it is really dirty, I may start with
soap and water and a toothbrush. Then I follow up with clean water,
then distilled water, and finally alcohol, and I don't worry about the
fact that it isn't 100% alcohol.

The purpose of the alcohol is to carry off as much of the water as
possible, so that it can't dry in place and leave any residue. A side
benefit is that the water that's in the alcohol will be extremely
pure. Of course the residue will be minimized by the sequence of
rinses above, but you can't always control what comes off the board.

If possible, use compressed air to blow the board off, thus minimizing
remaining fluid which will leave a residue when it drys in place.

And finally, you probably can't do any of this if your board includes
assemblies that water, etc, can get into but not easily back out. This
includes things like switches, pots, and transformers.

And then, of course, you have to thoroughly dry the board.

I have a friend who tells of starting his cleaning process by running
his boards thru the wash cycle of his kitchen dishwasher, with soap.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

In article ,
Jim Adney wrote:

I have a friend who tells of starting his cleaning process by running
his boards thru the wash cycle of his kitchen dishwasher, with soap.

Bob Pease swears by this process. He writes (in "Troubleshooting
Analog Circuits", a book I most strongly recommend) that when he's
working on PC-board circuits which require low leakage currents, he'll
run 'em through the dishwasher, standard cycle, using a normal load of
Calgonite detergent. When the wash and rinse are complete, he takes
them out, raps/shakes/blows off the rinse water, and stacks them in
the dishstrainer to dry.

He says that this process results in lower board-leakage currents than
the more traditional PC-board cleaning processes which use organic
solvents.

I believe that the use of Calgonite is significant - I looked it up
and found that it contains surfactants and calcium metasilicate, and
is significantly alkaline, but it does not contain chlorine. Other
powdered dish detergents (e.g. Cascade) do contain chlorine, and I
suspect that they might corrode components on a circuit board.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Dan Dubosky" wrote in
:


"mike" wrote in message
news:tUg8k.29$od.22@trnddc07...
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.

--
Good point, Mike. There may have been something on the cell phone board
that was not on my experimental board. I did however scrub the cell
phone board twice with Radio Shack Electronics Cleaner and I think that
there is still some effects left from the submersion. I only did the
experiment since I thought that some were suggesting that there was some
corrosive residue created by the material in the less than pure water,
but they may in fact have been referring to residue materials of the
type that you have suggested.

It is likely that some SMT components or other components still have
conductive residue between the part and the board.

I 'repaired' a laptop computer that had 'merlott' [wine] spilled in it.
It was left powered on over the weekend.

The repair consisted of
remove power sources
disassembly
Rinse with plenty of clean water
rinse with alcohol
scrubbing and scraping to remove visible conductive paths. rinse that area
with water and alcohol.
rebuilding a couple of conductors that had been eaten away
completely drying. Many hours of sitting in the flow of warm, dry air from
an air vent. The keyboard took a long time to dry.
reassembly.






--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

"bz" wrote in message
. 139...
"Dan Dubosky" wrote in
:


"mike" wrote in message
news:tUg8k.29$od.22@trnddc07...
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.

--
Good point, Mike. There may have been something on the cell phone board
that was not on my experimental board. I did however scrub the cell
phone board twice with Radio Shack Electronics Cleaner and I think that
there is still some effects left from the submersion. I only did the
experiment since I thought that some were suggesting that there was some
corrosive residue created by the material in the less than pure water,
but they may in fact have been referring to residue materials of the
type that you have suggested.

It is likely that some SMT components or other components still have
conductive residue between the part and the board.

I 'repaired' a laptop computer that had 'merlott' [wine] spilled in it.
It was left powered on over the weekend.

The repair consisted of
remove power sources
disassembly
Rinse with plenty of clean water
rinse with alcohol
scrubbing and scraping to remove visible conductive paths. rinse that area
with water and alcohol.
rebuilding a couple of conductors that had been eaten away
completely drying. Many hours of sitting in the flow of warm, dry air from
an air vent. The keyboard took a long time to dry.
reassembly.






--
bz 73 de N5BZ k

There's a board that I repair commercially, that comes from an automatic
drinks vending machine. Often, when I receive them, they are caked in
ingredient residue that has been flying about inside the machine, which
makes them pretty much impossible to work on, so the first thing they get is
a wash. I just run the water until it's coming out of the sink tap (faucet
for our U.S. colleagues ?) at its hottest, squirt a little ordinary washing
up liquid on the board, flick some of the hot water on with a pan-scrubbing
brush, and then work that up into a thick lather, scrubbing between the legs
of the through-hole components. When it's had a good scrub, it gets run
under that hot water stream, until all of the soap is off both sides. It
then gets shaken, patted dry on a dish towel, before being stood vertically
in front of an electric fan heater for about 5 minutes.

The result of all of this is a board that looks like it has just come out of
the factory, and I have never had any future problems with any residues, and
I've been doing it to this particular job for about 6 years now. As well as
through-hole components, this board also has many s.m. components on it,
including both I.C.s and passives. It does not, however, have any 'closed
in' components such as coils, IF transformers etc, which as someone else
suggested, would probably not take kindly to being flooded with water ...

Arfa

In article , Jim Adney wrote:
On Tue, 24 Jun 2008 21:28:04 -0400 "Dan Dubosky"
wrote:

Good point, Mike. There may have been something on the cell phone board
that was not on my experimental board. I did however scrub the cell phone
board twice with Radio Shack Electronics Cleaner and I think that there is
still some effects left from the submersion.

It sounds like you've been careful and thorough, but your board might
benefit from additional scrubbings in some other solvents, since not
everything is soluble in Radio Shack Electronics Cleaner.

In general, I clean things by starting with clean water, since it is
the most universal solvent. If it is really dirty, I may start with
soap and water and a toothbrush. Then I follow up with clean water,
then distilled water, and finally alcohol, and I don't worry about the
fact that it isn't 100% alcohol.

I have cleaned stubborn high impedance loading by using mostly alcohol
and the Weller air pencil set to a high flow and low temperature. The problems
were under the components. I sometimes have to repeat many times
before all the flux and residue is out. You have to move the air pencil around
under components, going mostly in one direction. The old boss made me use alcohol.

By the way, the cell phone I worked with appears to be OK after much cleaning, cyclic baking, and
a month delay.

greg

On Tue, 24 Jun 2008 21:50:46 -0700 (Dave Platt)
wrote:

In article ,
Jim Adney wrote:

I have a friend who tells of starting his cleaning process by running
his boards thru the wash cycle of his kitchen dishwasher, with soap.

Bob Pease swears by this process. He writes (in "Troubleshooting
Analog Circuits", a book I most strongly recommend) that when he's
working on PC-board circuits which require low leakage currents, he'll
run 'em through the dishwasher, standard cycle, using a normal load of
Calgonite detergent.

I have the book, and I read it years ago, but I'd forgotten that Bob
also did this.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

On Wed, 25 Jun 2008 15:42:52 GMT (GregS)
wrote:

I have cleaned stubborn high impedance loading by using mostly alcohol
and the Weller air pencil set to a high flow and low temperature. The problems
were under the components. I sometimes have to repeat many times
before all the flux and residue is out. You have to move the air pencil around
under components, going mostly in one direction. The old boss made me use alcohol.

Rosin flux doesn't dissolve completely in either water or alcohol, but
I've found that by alternating rinses, I can eventually remove it. In
cases like that, it might pay to invest in commercial flux remover, if
only to get things started. I'd still finish up with water and then
alcohol, however.

By the way, the cell phone I worked with appears to be OK after much cleaning, cyclic baking, and
a month delay.

In that case, there was probably something on the board that was just
hard to get the water out of. The real test will be to see whether it
continues to work in humid weather. That's when residue can resorb
moisture and start causing problems again.

If there's no residue, then humid weather should not cause any
problems.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

"Dan Dubosky" wrote in message
...
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

Many thanks to all of you. The cell phone now appears to be back to normal.
Yesterday, I purchased "denatured alcohol solvent" by a company called
Sunnyside. It was in a well sealed can with a plastic top that had to be
removed, and is said to contain denatured alcohol and less than 4% methanol.
I don't know its purity, but when I stuck my finger in it and it got under
my nail, it really burned.

I completely bathed the main circuit board in this solvent for about one
minute while brushing around the main side of the board. I then let it
completely dry for over 30 minutes, first in the sun and then under an
incandescent light.

I charged the cell phone up last night, and this morning there is no
significant discharge. The large SMT components have a sealant around their
base but many of the smaller components do not have such a sealant. So
moisture could easily have remained under them and within the many push
button switches.

Today is a very humid day so it will be interesting to see how much
discharge occurs.

Again, thanks to all.
Dan

Jim Adney wrote in
:

On Tue, 24 Jun 2008 21:50:46 -0700 (Dave Platt)
wrote:

In article ,
Jim Adney wrote:

I have a friend who tells of starting his cleaning process by running
his boards thru the wash cycle of his kitchen dishwasher, with soap.

Bob Pease swears by this process. He writes (in "Troubleshooting
Analog Circuits", a book I most strongly recommend) that when he's
working on PC-board circuits which require low leakage currents, he'll
run 'em through the dishwasher, standard cycle, using a normal load of
Calgonite detergent.

I have the book, and I read it years ago, but I'd forgotten that Bob
also did this.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------


I used to use the auto dishwasher trick at the Orlando TEK field office,on
2236 DMM boards,cured many leakage problems.used Calgonite,BTW.

And we had a drying oven that had a negative pressure inside.

--
Jim Yanik
jyanik
at
kua.net

Jim Yanik wrote:

snip
I used to use the auto dishwasher trick at the Orlando TEK field office,on
2236 DMM boards,cured many leakage problems.used Calgonite,BTW.

And we had a drying oven that had a negative pressure inside.


The TEK field office in St. Paul used to clean 500 series gear amongst
other things in a sort of dishwasher and also had the drying oven; was
this equipment standardized amongst the field offices?

Michael

msg wrote in
news
Jim Yanik wrote:

snip
I used to use the auto dishwasher trick at the Orlando TEK field
office,on 2236 DMM boards,cured many leakage problems.used
Calgonite,BTW.

And we had a drying oven that had a negative pressure inside.


The TEK field office in St. Paul used to clean 500 series gear amongst
other things in a sort of dishwasher and also had the drying oven; was
this equipment standardized amongst the field offices?

Michael


Heh,I washed down a lot of 500 series tube scopes!
It made a big difference,too.

well,everybody seems to have had different equipment for the task.
I had to persuade the Orlando manager to ship the old wash/spray booth from
the closed TEK-Indianapolis office,and their drying ovens were from
different manufacturers.Some TEK field offices had NO wash/dry facilities.
(moot point now;they're all closed.)

I had to take boards home to run through MY dishwasher.
I didn't know of any TEK offices that had a auto dishwasher.

--
Jim Yanik
jyanik
at
kua.net

Dave Platt wrote:
In article ,
Jim Adney wrote:

I have a friend who tells of starting his cleaning process by running
his boards thru the wash cycle of his kitchen dishwasher, with soap.

Bob Pease swears by this process. He writes (in "Troubleshooting
Analog Circuits", a book I most strongly recommend) that when he's
working on PC-board circuits which require low leakage currents, he'll
run 'em through the dishwasher, standard cycle, using a normal load of
Calgonite detergent. When the wash and rinse are complete, he takes
them out, raps/shakes/blows off the rinse water, and stacks them in
the dishstrainer to dry.

He says that this process results in lower board-leakage currents than
the more traditional PC-board cleaning processes which use organic
solvents.

I believe that the use of Calgonite is significant - I looked it up
and found that it contains surfactants and calcium metasilicate, and
is significantly alkaline, but it does not contain chlorine. Other
powdered dish detergents (e.g. Cascade) do contain chlorine, and I
suspect that they might corrode components on a circuit board.

I have to side with Bob Pease. Over the years of reading his column in
Electronic Design, and stuff in NSC's data books, he has had tons of
experience with analog and is usually dead on. He was behind the now
classic 'Floobydust' data book back in 1977. Back then everything was
washed in a freon solvent tank but times have changed, no more freon
tanks, Lead is being banned, etc.
I never dismiss his stuff as rambling since he almost always puts in a
nugget or two.
Bill Baka