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Cap Leakage
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ABLE1
Jul 14, 2017, 8:45:38 PM7/14/17
to
Hello all,
I have a sound amplifier board with what looks like some 25v 220mfd
radial capacitors that appear to have leaked some of the electrolyte on
to the board. The board is easily 20+ years old.
One of the IC chips that is in the area appears to have some corrosion
on the pins.
If someone would be so kind to answer my questions they are as follows:
Is the electrolyte some kind of acid base??
Will washing the board with contact cleaner properly clean
and or neutralize the effects??
I plan on replacing the bad capacitors but want to be sure I am
not missing something. I don't want to replace the chip unless
it is damaged in some way.
Thanks for any hints or tip on this matter.
Have a good day.
Les
I have a sound amplifier board with what looks like some 25v 220mfd
radial capacitors that appear to have leaked some of the electrolyte on
to the board. The board is easily 20+ years old.
One of the IC chips that is in the area appears to have some corrosion
on the pins.
If someone would be so kind to answer my questions they are as follows:
Is the electrolyte some kind of acid base??
Will washing the board with contact cleaner properly clean
and or neutralize the effects??
I plan on replacing the bad capacitors but want to be sure I am
not missing something. I don't want to replace the chip unless
it is damaged in some way.
Thanks for any hints or tip on this matter.
Have a good day.
Les
tom
Jul 14, 2017, 8:51:00 PM7/14/17
to
"ABLE1" <som...@nowhere.net> wrote in message
news:NAdaB.89557$5A2....@fx28.iad...
a brush to scrub where there is corrosion.
Dry in oven at 50-60 °C for several hours.
Phil Allison
Jul 14, 2017, 11:31:39 PM7/14/17
to
ABLE1 wrote:
----------------
> Will washing the board with contact cleaner properly clean
> and or neutralize the effects??
>
** Contact cleaner is undefined, can be damn near anything.
I use a "Circuit Boaord Cleaner" that has a combination of hydrocarbon solvents and dries quickly.
> I plan on replacing the bad capacitors but want to be sure I am
> not missing something. I don't want to replace the chip unless
> it is damaged in some way.
** Clean it up best you can and watch out if electrolyte has gone underneath.
I have found a small fibreglass brush useful.
http://au.element14.com/duratool/d02266/pen-pcb-cleaning-fibreglass-4mm/dp/2102028
Really bad cases may need immersion in hot, detergent water to come good.
.... Phil
----------------
>
>
> I have a sound amplifier board with what looks like some 25v 220mfd
> radial capacitors that appear to have leaked some of the electrolyte on
> to the board. The board is easily 20+ years old.
>
> One of the IC chips that is in the area appears to have some corrosion
> on the pins.
>
> If someone would be so kind to answer my questions they are as follows:
>
> Is the electrolyte some kind of acid base??
>
** It's usually ethylene glycol plus boric acid and loves to attack copper.
>
> I have a sound amplifier board with what looks like some 25v 220mfd
> radial capacitors that appear to have leaked some of the electrolyte on
> to the board. The board is easily 20+ years old.
>
> One of the IC chips that is in the area appears to have some corrosion
> on the pins.
>
> If someone would be so kind to answer my questions they are as follows:
>
> Is the electrolyte some kind of acid base??
>
> Will washing the board with contact cleaner properly clean
> and or neutralize the effects??
>
I use a "Circuit Boaord Cleaner" that has a combination of hydrocarbon solvents and dries quickly.
> I plan on replacing the bad capacitors but want to be sure I am
> not missing something. I don't want to replace the chip unless
> it is damaged in some way.
I have found a small fibreglass brush useful.
http://au.element14.com/duratool/d02266/pen-pcb-cleaning-fibreglass-4mm/dp/2102028
Really bad cases may need immersion in hot, detergent water to come good.
.... Phil
tabb...@gmail.com
Jul 15, 2017, 7:16:55 AM7/15/17
to
NT
ABLE1
Jul 15, 2017, 8:09:57 AM7/15/17
to
I get the idea on cleaning. BTW as for "Contact Cleaner" I was
referring to this one.
https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
Or similar, but may not be the most desired.
Phil, as for the term "Circuit Board Cleaner" is there a specific brand
that you use??
Presently searching for replacement caps. Once I acquire them I will
dive into this project.
Another question: Concerning the chip that has been effected. Can or
could the electrolyte leach into the chips at the pins and cause
problems with the chip in some way?? Or is the chip considered
hermetically sealed is some fashion??
Thanks again!! Do appreciate the insight.
Les
tabb...@gmail.com
Jul 15, 2017, 8:14:30 AM7/15/17
to
On Saturday, 15 July 2017 13:09:57 UTC+1, ABLE1 wrote:
> Tom, NT, Phil, Thanks for all the input.
>
> I get the idea on cleaning. BTW as for "Contact Cleaner" I was
> referring to this one.
>
> https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
> Or similar, but may not be the most desired.
>
> Phil, as for the term "Circuit Board Cleaner" is there a specific brand
> that you use??
>
> Presently searching for replacement caps. Once I acquire them I will
> dive into this project.
>
> Another question: Concerning the chip that has been effected. Can or
> could the electrolyte leach into the chips at the pins and cause
> problems with the chip in some way?? Or is the chip considered
> hermetically sealed is some fashion??
>
> Thanks again!! Do appreciate the insight.
>
> Les
if they weren't sealed they wouldn't last long
> Tom, NT, Phil, Thanks for all the input.
>
> I get the idea on cleaning. BTW as for "Contact Cleaner" I was
> referring to this one.
>
> https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
> Or similar, but may not be the most desired.
>
> Phil, as for the term "Circuit Board Cleaner" is there a specific brand
> that you use??
>
> Presently searching for replacement caps. Once I acquire them I will
> dive into this project.
>
> Another question: Concerning the chip that has been effected. Can or
> could the electrolyte leach into the chips at the pins and cause
> problems with the chip in some way?? Or is the chip considered
> hermetically sealed is some fashion??
>
> Thanks again!! Do appreciate the insight.
>
> Les
NT
ABLE1
Jul 15, 2017, 12:25:07 PM7/15/17
to
I got it. Was just wondering if the "seal" would be
effected by the leaking electrolyte is some way.
As a general question on these capacitors that leaked.
Given the age (20+ years) would it be that they would
have been effected by a power surge or just old age.
There are other radial caps on the board of the same size
and value that do not show any leakage.
I am asking in respect that given the condition should I
just replace them all or only those that have leaked??
For me this is more of a fun experiment of sorts. I have
been working with various electronics for 40++ years or so.
Running my own business for the past 29 years.
I have in the past but rarely have I gotten down to board level.
As you can guess, if a component or board failed it was trash it
and install a new. For critical devices it is not worth the time
and liability to play around with board components.
This project is quite different. I have already replaced the sound
board with another and the repair project is completed.
Just waiting to be paid. :-)
I just want to see if my observation as to the condition of the caps was
the real problem and can I fix it by doing a little board de-soldering,
etc. Already on Digi-Key trying to source replacements.
Again, thanks for the hints. Have a good rest of your weekend.
Les
Jon Elson
Jul 15, 2017, 2:13:18 PM7/15/17
to
ABLE1 wrote:
>
> Another question: Concerning the chip that has been effected. Can or
> could the electrolyte leach into the chips at the pins and cause
> problems with the chip in some way?? Or is the chip considered
> hermetically sealed is some fashion??
The typical commercial chips are epoxy molded around the lead frame and IC.
>
> Another question: Concerning the chip that has been effected. Can or
> could the electrolyte leach into the chips at the pins and cause
> problems with the chip in some way?? Or is the chip considered
> hermetically sealed is some fashion??
So, the "seal" is just metal leads molded into the plastic body. Given
enough time and humidity, it is possible for the leaked electrolyte or any
other corrosive stuff to work its way along the lead and get to the bonding
wires or the IC itself. Not real common, but it CAN happen.
Military/aerospace chips are more hermetic, with kovar leads fused into a
glass seal. But, enough corrosive stuff can get into those, too. it just
takes longer.
Jon
ABLE1
Jul 15, 2017, 4:39:58 PM7/15/17
to
I understand. At this point I am going to replace the caps and see what
happens. Hopefully that will be the complete fix.
Les
tabb...@gmail.com
Jul 15, 2017, 8:53:06 PM7/15/17
to
On Saturday, 15 July 2017 17:25:07 UTC+1, ABLE1 wrote:
> As a general question on these capacitors that leaked.
> Given the age (20+ years) would it be that they would
> have been effected by a power surge or just old age.
old age and/or lack of power
> There are other radial caps on the board of the same size
> and value that do not show any leakage.
>
> I am asking in respect that given the condition should I
> just replace them all or only those that have leaked??
Given the bad state of some caps it's likely there are others that have gone high ESR and/or low capacity but not leaked. Most folk would replace the lot. You can get a £12 chinese component tester that'll tell you real capacity & ESR. See ebay, amazon, banggood etc.
NT
> On 7/15/2017 8:14 AM, tabbypurr wrote:
> > On Saturday, 15 July 2017 13:09:57 UTC+1, ABLE1 wrote:
> >
> >> Tom, NT, Phil, Thanks for all the input.
> >>
> >> I get the idea on cleaning. BTW as for "Contact Cleaner" I was
> >> referring to this one.
> >>
> >> https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
> >> Or similar, but may not be the most desired.
> >>
> >> Phil, as for the term "Circuit Board Cleaner" is there a specific brand
> >> that you use??
> >>
> >> Presently searching for replacement caps. Once I acquire them I will
> >> dive into this project.
> >>
> >> Another question: Concerning the chip that has been effected. Can or
> >> could the electrolyte leach into the chips at the pins and cause
> >> problems with the chip in some way?? Or is the chip considered
> >> hermetically sealed is some fashion??
> >>
> >> Thanks again!! Do appreciate the insight.
> >>
> >> Les
> >
> > if they weren't sealed they wouldn't last long
> >
> >
> > NT
> >
>
> Thanks NT,
>
> I got it. Was just wondering if the "seal" would be
> effected by the leaking electrolyte is some way.
as said it's epoxy on metal so not likely.
> > On Saturday, 15 July 2017 13:09:57 UTC+1, ABLE1 wrote:
> >
> >> Tom, NT, Phil, Thanks for all the input.
> >>
> >> I get the idea on cleaning. BTW as for "Contact Cleaner" I was
> >> referring to this one.
> >>
> >> https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
> >> Or similar, but may not be the most desired.
> >>
> >> Phil, as for the term "Circuit Board Cleaner" is there a specific brand
> >> that you use??
> >>
> >> Presently searching for replacement caps. Once I acquire them I will
> >> dive into this project.
> >>
> >> Another question: Concerning the chip that has been effected. Can or
> >> could the electrolyte leach into the chips at the pins and cause
> >> problems with the chip in some way?? Or is the chip considered
> >> hermetically sealed is some fashion??
> >>
> >> Thanks again!! Do appreciate the insight.
> >>
> >> Les
> >
> > if they weren't sealed they wouldn't last long
> >
> >
> > NT
> >
>
> Thanks NT,
>
> I got it. Was just wondering if the "seal" would be
> effected by the leaking electrolyte is some way.
> As a general question on these capacitors that leaked.
> Given the age (20+ years) would it be that they would
> have been effected by a power surge or just old age.
> There are other radial caps on the board of the same size
> and value that do not show any leakage.
>
> I am asking in respect that given the condition should I
> just replace them all or only those that have leaked??
NT
Phil Allison
Jul 16, 2017, 7:51:23 AM7/16/17
to
ABLE1 wrote:
--------------------
>
> Tom, NT, Phil, Thanks for all the input.
>
> I get the idea on cleaning. BTW as for "Contact Cleaner" I was
> referring to this one.
>
> https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
> Or similar, but may not be the most desired.
>
> Phil, as for the term "Circuit Board Cleaner" is there a specific brand
> that you use??
>
>
** The brand I use is " RF " ( Richard Foot Pty Ltd ), available only here in Australia, AFAIK
The CRC product you linked is likely similar - simple, fast evaporating hydrocarbon solvent.
.... Phil
--------------------
>
> Tom, NT, Phil, Thanks for all the input.
>
> I get the idea on cleaning. BTW as for "Contact Cleaner" I was
> referring to this one.
>
> https://www.zoro.com/crc-electronic-component-cleaner-13-oz-02200/i/G8578595/
> Or similar, but may not be the most desired.
>
> Phil, as for the term "Circuit Board Cleaner" is there a specific brand
> that you use??
>
>
The CRC product you linked is likely similar - simple, fast evaporating hydrocarbon solvent.
.... Phil
ABLE1
Jul 16, 2017, 9:54:30 AM7/16/17
to
Most impressive....................
and they do Chocolate as well.............
COOL!!!
Les
olds...@tubes.com
Jul 16, 2017, 4:40:58 PM7/16/17
to
On Fri, 14 Jul 2017 20:51:30 -0400, "tom" <tmille...@verizon.net>
wrote:
I dont know if I'd place any electronics in an oven. Heat destroys
components. Just sit it in the sun on a sunny day and it will dry. I
have washed computer motherboards, including the power supplies, and
hosed them off. (to remove all that dirt that builds up on that stuff),
then left them out in the sun for a full day to dry, and they always
work just fine.
wrote:
components. Just sit it in the sun on a sunny day and it will dry. I
have washed computer motherboards, including the power supplies, and
hosed them off. (to remove all that dirt that builds up on that stuff),
then left them out in the sun for a full day to dry, and they always
work just fine.
Ralph Mowery
Jul 16, 2017, 6:48:07 PM7/16/17
to
In article <irfnmclaqsfrc3do6...@4ax.com>,
olds...@tubes.com says...
that is out in the sun in the summer.
olds...@tubes.com says...
>
>
>
> I dont know if I'd place any electronics in an oven. Heat destroys
> components. Just sit it in the sun on a sunny day and it will dry. I
> have washed computer motherboards, including the power supplies, and
> hosed them off. (to remove all that dirt that builds up on that stuff),
> then left them out in the sun for a full day to dry, and they always
> work just fine.
My oven will not regulate that low, so I put the wet equipment in a car
>
>
> I dont know if I'd place any electronics in an oven. Heat destroys
> components. Just sit it in the sun on a sunny day and it will dry. I
> have washed computer motherboards, including the power supplies, and
> hosed them off. (to remove all that dirt that builds up on that stuff),
> then left them out in the sun for a full day to dry, and they always
> work just fine.
that is out in the sun in the summer.
ABLE1
Jul 16, 2017, 8:09:28 PM7/16/17
to
Phil Allison
Jul 16, 2017, 8:28:31 PM7/16/17
to
Ralph Mowery wrote:
> >
> > I dont know if I'd place any electronics in an oven. Heat destroys
> > components. Just sit it in the sun on a sunny day and it will dry. I
> > have washed computer motherboards, including the power supplies, and
> > hosed them off. (to remove all that dirt that builds up on that stuff),
> > then left them out in the sun for a full day to dry, and they always
> > work just fine.
>
> My oven will not regulate that low, so I put the wet equipment in a car
> that is out in the sun in the summer.
>
>
** The trick is to bring the oven up to about 100C, then turn it off.
> >
> > I dont know if I'd place any electronics in an oven. Heat destroys
> > components. Just sit it in the sun on a sunny day and it will dry. I
> > have washed computer motherboards, including the power supplies, and
> > hosed them off. (to remove all that dirt that builds up on that stuff),
> > then left them out in the sun for a full day to dry, and they always
> > work just fine.
>
> My oven will not regulate that low, so I put the wet equipment in a car
> that is out in the sun in the summer.
>
>
Place the item inside and close the door, it will heat to about 75C and be dry as a bone in 15 minutes. Take it out and let it cool.
75C is not hazardous to electronic components.
.... Phil
ABLE1
Jul 16, 2017, 8:38:43 PM7/16/17
to
Thanks Phil,
Les
jurb...@gmail.com
Jul 17, 2017, 9:37:10 PM7/17/17
to
I used to have a different approach. This happened to Mitsubishi TVs alot because of electrolyte leaks. But I had a different problem sometimes and that was coolant leaks. Both substances act pretty much the same. At first, on the board they are pretty innocuous, but after a little time and voltage put across them they became corrosive and conductive.
But the caps themselves, I stopped changing them. Maybe they're doe leaking.
I took the board out for this. I started with acetone, and then alcohol. Brushed the hell out of it both times. Then rinsed it in the sink in hot water. This place had restaurant hot water. Remember to flood and brush both sides of the board. Then dry it with a hair dryer. Dry both sides, that gets the trapped water out of your SMDs.
Repeat. I shit you not. And after that inspect and make sure you see no wet spots after the board is supposedly dry. That might be the remains of the chemical.
That's how I used to do it. It worked.
But the caps themselves, I stopped changing them. Maybe they're doe leaking.
I took the board out for this. I started with acetone, and then alcohol. Brushed the hell out of it both times. Then rinsed it in the sink in hot water. This place had restaurant hot water. Remember to flood and brush both sides of the board. Then dry it with a hair dryer. Dry both sides, that gets the trapped water out of your SMDs.
Repeat. I shit you not. And after that inspect and make sure you see no wet spots after the board is supposedly dry. That might be the remains of the chemical.
That's how I used to do it. It worked.
John-Del
Jul 17, 2017, 9:53:48 PM7/17/17
to
ABLE1
Jul 17, 2017, 10:27:14 PM7/17/17
to
clean and dry out a board.
Scary too, I might choose the wrong one to do this one board??
Fear not guys................. I will choose wisely.....................
OR
DO THEM ALL just for fun, since I am confident that they all will
be equally effective.
But in what order.................. hmmmmmmmmmm
Les
tabb...@gmail.com
Jul 18, 2017, 3:38:41 AM7/18/17
to
On Tuesday, 18 July 2017 03:27:14 UTC+1, ABLE1 wrote:
> Ok, by my count we now have 6 totally different ways to
> clean and dry out a board.
>
> Scary too, I might choose the wrong one to do this one board??
>
> Fear not guys................. I will choose wisely.....................
>
> OR
>
> DO THEM ALL just for fun, since I am confident that they all will
> be equally effective.
>
> But in what order.................. hmmmmmmmmmm
>
> Les
OK, here's number 7. Put it in a domestic dishwasher then warm room dry for a week.
> Ok, by my count we now have 6 totally different ways to
> clean and dry out a board.
>
> Scary too, I might choose the wrong one to do this one board??
>
> Fear not guys................. I will choose wisely.....................
>
> OR
>
> DO THEM ALL just for fun, since I am confident that they all will
> be equally effective.
>
> But in what order.................. hmmmmmmmmmm
>
> Les
What does it matter? All you're doing is washing & drying.
NT
ABLE1
Jul 22, 2017, 3:32:11 PM7/22/17
to
I removed all the leaking caps plus the others of the same type
and size that had not shown signs of leakage just to be thorough.
I then cleaned the board with some mild detergent, rinsed off
and placed in my pre-heated oven at 220F and then turned off.
Let set in the oven for about 2 hours while it cooled. Pulled
the board out and it looks good.
So far so good. It is now time to install the new caps.
And then it hit me.
This is a double sided board. I am concerned that the component
side of the board that is under the capacitor will not be soldered
properly to the leads.
Is there some trick that needs to be applied somehow to get this
soldered properly??
Again thanks for any thoughts or suggestions.
Les
Ralph Mowery
Jul 22, 2017, 4:30:40 PM7/22/17
to
In article <XKNcB.239890$OD2.1...@fx44.iad>, som...@nowhere.net
says...
path through the hole to the other side that is conductive. Just use
plenty of solder and heat and it should wick to the other side.
says...
>
>
> So far so good. It is now time to install the new caps.
>
> And then it hit me.
>
> This is a double sided board. I am concerned that the component
> side of the board that is under the capacitor will not be soldered
> properly to the leads.
>
> Is there some trick that needs to be applied somehow to get this
> soldered properly??
>
>
Hopefully the holes are waht they call 'plated through' where there is a
>
> So far so good. It is now time to install the new caps.
>
> And then it hit me.
>
> This is a double sided board. I am concerned that the component
> side of the board that is under the capacitor will not be soldered
> properly to the leads.
>
> Is there some trick that needs to be applied somehow to get this
> soldered properly??
>
>
path through the hole to the other side that is conductive. Just use
plenty of solder and heat and it should wick to the other side.
ABLE1
Jul 22, 2017, 6:42:16 PM7/22/17
to
On 7/22/2017 4:30 PM, Ralph Mowery wrote:
> In article <XKNcB.239890$OD2.1...@fx44.iad>, som...@nowhere.net
> says...
>>
>>
>> So far so good. It is now time to install the new caps.
>>
>> And then it hit me.
>>
>> This is a double sided board. I am concerned that the component
>> side of the board that is under the capacitor will not be soldered
>> properly to the leads.
>>
>> Is there some trick that needs to be applied somehow to get this
>> soldered properly??
>>
>>
>
> Hopefully the holes are what they call 'plated through' where there is a
> In article <XKNcB.239890$OD2.1...@fx44.iad>, som...@nowhere.net
> says...
>>
>>
>> So far so good. It is now time to install the new caps.
>>
>> And then it hit me.
>>
>> This is a double sided board. I am concerned that the component
>> side of the board that is under the capacitor will not be soldered
>> properly to the leads.
>>
>> Is there some trick that needs to be applied somehow to get this
>> soldered properly??
>>
>>
>
> path through the hole to the other side that is conductive. Just use
> plenty of solder and heat and it should wick to the other side.
>
>
Thanks Ralph,
> plenty of solder and heat and it should wick to the other side.
>
>
That was the key point I was missing. I metered each side of the board
on one hole, and yes, I got continuity.
Excellent!! Sooooooooo "Piece of cake".
Thanks again.
Les
tabb...@gmail.com
Jul 22, 2017, 8:54:08 PM7/22/17
to
If electronics ever becomes edible that would solve the disposal issue.
NT
ABLE1
Jul 22, 2017, 9:05:20 PM7/22/17
to
Phil Allison
Jul 22, 2017, 9:33:44 PM7/22/17
to
ABLE1 wrote:
------------------
> >
>
> Ok, Update and another question.
>
> I removed all the leaking caps plus the others of the same type
> and size that had not shown signs of leakage just to be thorough.
>
** FFS stop using the term "leakage" wrongly.
In electronics, "leakage" refers to current passing through an imperfect insulator.
What you have is caps *leaking electrolyte*.
>
> And then it hit me.
>
> This is a double sided board. I am concerned that the component
> side of the board that is under the capacitor will not be soldered
> properly to the leads.
>
** That makes no sense.
You can see the component side and solder to it.
The reverse side may be a problem to get at, but nearly all PCBs have plated through holes that you can solder from EITHER side.
..... Phil
------------------
> >
>
> Ok, Update and another question.
>
> I removed all the leaking caps plus the others of the same type
> and size that had not shown signs of leakage just to be thorough.
>
In electronics, "leakage" refers to current passing through an imperfect insulator.
What you have is caps *leaking electrolyte*.
>
> And then it hit me.
>
> This is a double sided board. I am concerned that the component
> side of the board that is under the capacitor will not be soldered
> properly to the leads.
>
You can see the component side and solder to it.
The reverse side may be a problem to get at, but nearly all PCBs have plated through holes that you can solder from EITHER side.
..... Phil
ABLE1
Jul 22, 2017, 10:32:16 PM7/22/17
to
Mental note made.
Les
John-Del
Jul 23, 2017, 12:13:27 AM7/23/17
to
On Saturday, July 22, 2017 at 3:32:11 PM UTC-4, ABLE1 wrote:
>
> This is a double sided board. I am concerned that the component
> side of the board that is under the capacitor will not be soldered
> properly to the leads.
>
> Is there some trick that needs to be applied somehow to get this
> soldered properly??
You now know about the plated-through holes, but be aware that while they show continuity now, they may not after soldering. Some manufacturers do not feature sturdy plating in the holes (Samsung is one), and the added leaked electrolyte can aggravate it.
>
> This is a double sided board. I am concerned that the component
> side of the board that is under the capacitor will not be soldered
> properly to the leads.
>
> Is there some trick that needs to be applied somehow to get this
> soldered properly??
Preheat the board, apply solder flux, use sufficient solder tip heat and carefully insert the capacitors through the holes. Don't force them like you might do on a single sided board.
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