Exploding Capacitors

S

Searcher7

Guest
Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

I blew a capacitor on a game board I'm trying to get working and the
only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/BlownCapacitor.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-TopA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-BottomA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariRegulator-AudioPCB-A035435-02.jpg

Thanks.

Darren Harris
Staten Island, New York.
 
"Searcher7" wrote in message
news:bd4ec732-92ee-4f0d-b4cf-9c8d1d3aae9c@eb1g2000vbb.googlegroups.com...

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

I blew a capacitor on a game board I'm trying to get working and the
only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/BlownCapacitor.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-TopA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-BottomA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariRegulator-AudioPCB-A035435-02.jpg

Thanks.

Darren Harris
Staten Island, New York.

I ancient times, circa (when I was a young tech) it happened quite often.
In modern times I have only seen an "explosion" rarely and ones that were
done on purpose by angelic students.
A malfunction that would cause AC across an electrolytic could do this.
Reverse polarity or serious over-voltage, maybe.

Tom
 
On Sun, 3 Jul 2011, Searcher7 wrote:

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

What kind of capacitors? Generally capacitors won't explode, so you have
Click to expand...
to do something significant. Like a really big spike.

Or put a tantalum capacitor in backwards, and it will explode. I can't
remember for average electrolytics, it's been a while since I put one in
backwards

Michael

I blew a capacitor on a game board I'm trying to get working
and the
only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/BlownCapacitor.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-TopA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-BottomA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariRegulator-AudioPCB-A035435-02.jpg

Thanks.

Darren Harris
Staten Island, New York.
Click to expand...
 
On Sun, 3 Jul 2011 20:37:28 -0400, Michael Black <et472@ncf.ca> wrote:

On Sun, 3 Jul 2011, Searcher7 wrote:

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

What kind of capacitors? Generally capacitors won't explode, so you have
to do something significant. Like a really big spike.

Or put a tantalum capacitor in backwards, and it will explode. I can't
remember for average electrolytics, it's been a while since I put one in
backwards
Click to expand...
Tantalums will certainly explode and they don't have to be put in backwards to
let loose. They should never be operated at more than 50% of their rated
capacity. Other types can explode, too. Capacitors store energy and can let
it loose quickly. That's what they do.
 
On Jul 3, 5:37 pm, Michael Black <et...@ncf.ca> wrote:
On Sun, 3 Jul 2011, Searcher7 wrote:
Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

What kind of capacitors?  Generally capacitors won't explode, so you have
to do something significant.  Like a really big spike.

Or put a tantalum capacitor in backwards, and it will explode.  I can't
remember for average electrolytics, it's been a while since I put one in
backwards

   Michael

  > I blew a capacitor on a game board I'm trying to get working
and the







only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...

Thanks.

Darren Harris
Staten Island, New York.
Click to expand...
Well the game board used to work. I have a second board that I don't
want to take chances with and plug in until I know what happened.

The info on the capacitor which is in the same place as the exploding
one on the other board is as follows:

"ITT / 130.OU / 35.0S"

It would be the little black cap in between the +15V and +22V test
points in this picture:
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariMillipedePCB.jpg

When the cap blew I was testing the Regulator/Audio PCB, which was
measuring ok where it puts out -5VDC:
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariRegulator-AudioPCB-A035435-02.jpg

(All voltages on the AR PCB were tested within 2V of spec).

Right now I'm searching ofor info to see it the transformer could be
the culprit:
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-TopA035888.jpg

Thanks.

Darren Harris
Staten Island, New York.
 
"Searcher7"

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.
Click to expand...

** There are many reasons why an aluminium electro might explode:

1. DC voltage in excess of rating applied.

2. Reverse DC voltage applied.

3. The cap had become de-polarised ( eg through old age) and lost voltage
rating.

4. Internal short in cap.

In all cases, energy from the power supply heats the electrolyte inside the
cap to boiling point and the pressure build up causes it to eventually
explode.

At the time of explosion, vapour will be emitted and a rather nasty smell.

Your case sounds like #3.


..... Phil
 
I am going to guess you have the 1977 version of "MILLIPEDE". The following
seem to pertain to the 1982 version.

Here is a service manual
http://www.arcade-museum.com/manuals-videogames/M/Millipede.pdf

And a board for sale.
http://cgi.ebay.com/MILLIPEDE-ATARI-WORKING-ARCADE-CIRCUIT-BOARD-PCB-1352-/170638046085?pt=LH_DefaultDomain_0&hash=item27bad1f385
Make note of the statement about this model having power supply problems.

Here is a schematic
http://www.arcade-museum.com/manuals-videogames/M/Millipede-sp.pdf

On the schematic page 6 bottom left hand corner is C39 100uF 35V going to
the input of VR1 a 7815 regulator. With 22 VDC on a 35 volt capacitor it
should be safe. When electrolytics dry out the ESR goes up which would
exacerbate a heating problem.

Being the parts are 35 years old they could have dried out and failed. That
is why they have replacement parts.

Did you acquire it with the failed part or did it die on you? Good luck.


"Searcher7" <Searcher7@mail.con2.com> wrote in message
news:bd4ec732-92ee-4f0d-b4cf-9c8d1d3aae9c@eb1g2000vbb.googlegroups.com...
Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

I blew a capacitor on a game board I'm trying to get working and the
only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/BlownCapacitor.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-TopA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariTransformerAssembly-BottomA035888.jpg
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/AtariRegulator-AudioPCB-A035435-02.jpg

Thanks.

Darren Harris
Staten Island, New York.
Click to expand...
 
In <97d1abFqjqU1@mid.individual.net>, Phil Allison wrote:
"Searcher7"

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

** There are many reasons why an aluminium electro might explode:

1. DC voltage in excess of rating applied.

2. Reverse DC voltage applied.

3. The cap had become de-polarised ( eg through old age) and lost voltage
rating.

4. Internal short in cap.
Click to expand...
5. Excessive ripple current through the cap - usually due to faulty
choice of a cap that can't handle the ripple current.

6. Aging cap has increased resistance and decreased ripple current
handling.

7. Excessively hot environment.

In all cases, energy from the power supply heats the electrolyte inside
the cap to boiling point and the pressure build up causes it to
eventually explode.
Click to expand...
Sometimes they vent steam, often with liquid leakage, without exploding.

At the time of explosion, vapour will be emitted and a rather nasty smell.

Your case sounds like #3.
Click to expand...
Likely true.

--
- Don Klipstein (don@donklipstein.com)
 
"Don Klipstein Fucking Prick "


5. Excessive ripple current through the cap - usually due to faulty
choice of a cap that can't handle the ripple current.
Click to expand...
** High ripple current causes an electro to heat, the ESR then drops
dramatically and the problem solves itself.

If the choice of cap is really bad, failure will occur in the first
minutes of use.

So that scenario will never be seen in commercial equipment.

Sometimes they vent steam, often with liquid leakage, without exploding.
Click to expand...
** Can you see the heading ???

Fuckhead.



..... Phil
 
"Don Klipstein Fucking Prick "

5. Excessive ripple current through the cap - usually due to faulty
choice of a cap that can't handle the ripple current.

** High ripple current causes an electro to heat, the ESR then drops
dramatically and the problem solves itself.

The ripple current rating of a cap is for maximum safe.
Click to expand...

** Absolute BULLSHIT !!

Go read one sometime.


If the choice of cap is really bad, failure will occur in the first
minutes of use.

If the choice of cap is only mildly bad,
Click to expand...

** Irrelevant to my point or your point 5.

Fuckhead.


.... Phil
 
On Jul 4, 8:42 am, "Herman" <r...@bellsouth.net> wrote:
I am going to guess you have the 1977 version of "MILLIPEDE".  The following
seem to pertain to the 1982 version.

Here is a service manualhttp://www.arcade-museum.com/manuals-videogames/M/Millipede.pdf

And a board for sale.http://cgi.ebay.com/MILLIPEDE-ATARI-WORKING-ARCADE-CIRCUIT-BOARD-PCB-...
Make note of the statement about this model having power supply problems.

Here is a schematichttp://www.arcade-museum.com/manuals-videogames/M/Millipede-sp.pdf

On the schematic page 6 bottom left hand corner is C39 100uF 35V going to
the input of VR1 a 7815 regulator.  With 22 VDC on a 35 volt capacitor it
should be safe.  When electrolytics dry out the ESR goes up which would
exacerbate a heating problem.

Being the parts are 35 years old they could have dried out and failed.  That
is why they have replacement parts.

Did you acquire it with the failed part or did it die on you?  Good luck.

"Searcher7" <Search...@mail.con2.com> wrote in message

news:bd4ec732-92ee-4f0d-b4cf-9c8d1d3aae9c@eb1g2000vbb.googlegroups.com...







Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

I blew a capacitor on a game board I'm trying to get working and the
only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...

Thanks.

Darren Harris
Staten Island, New York.
Click to expand...
There are three of those type of caps on the Millipede PCB. And yes
the board is from 1982.

I made an error in reading the info off the cap thanks to the dust,
but the info is as follows:
"ITT" "100.OU" "35.OS" "A x" "-40•85° C" (I'm just not sure if
the O's are really zeroes).

On my spare Millipede PCB it is the cap on the right:
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/MillipedePCBCapacitor.jpg

On another test point at just before the cap exploded I got a reading
of +24.94V. Was almost 3V over spec too high? (Perhaps that voltage in
combination with it being an old cap cause it to explode).

And should I replace the chipped regular in that image?

(I really have to learn how to read schematics).

Thanks a lot.

Darren Harris
Staten Island, New York.
 
In article <97er53FmasU1@mid.individual.net>, Phil Allison wrote:
"Don Klipstein Fucking Prick "

5. Excessive ripple current through the cap - usually due to faulty
choice of a cap that can't handle the ripple current.

** High ripple current causes an electro to heat, the ESR then drops
dramatically and the problem solves itself.
Click to expand...
The ripple current rating of a cap is for maximum safe. This includes
whatever reliable effects of the cap adapting to ripple current.

If the choice of cap is really bad, failure will occur in the first
minutes of use.
Click to expand...
If the choice of cap is only mildly bad, then it can hold up through
some fair part of its rated life expectancy and then fail as aging
decreases its ripple current handling capability.

So that scenario will never be seen in commercial equipment.

Sometimes they vent steam, often with liquid leakage, without exploding.

** Can you see the heading ???

Fuckhead.

.... Phil
--
Click to expand...
- Don Klipstein (don@donklipstein.com)
 
yep that transistor with a crack in it looks very suspect maybe cap dried
out low resistance over heated transistor, transistor shorts full voltage
to cap (boom).



"Searcher7" <Searcher7@mail.con2.com> wrote in message
news:53346aa7-6553-49ae-b6c8-c57fdf0caba1@c41g2000yqm.googlegroups.com...
On Jul 4, 8:42 am, "Herman" <r...@bellsouth.net> wrote:
I am going to guess you have the 1977 version of "MILLIPEDE". The
following
seem to pertain to the 1982 version.

Here is a service
manualhttp://www.arcade-museum.com/manuals-videogames/M/Millipede.pdf

And a board for
sale.http://cgi.ebay.com/MILLIPEDE-ATARI-WORKING-ARCADE-CIRCUIT-BOARD-PCB-...
Make note of the statement about this model having power supply problems.

Here is a
schematichttp://www.arcade-museum.com/manuals-videogames/M/Millipede-sp.pdf

On the schematic page 6 bottom left hand corner is C39 100uF 35V going to
the input of VR1 a 7815 regulator. With 22 VDC on a 35 volt capacitor it
should be safe. When electrolytics dry out the ESR goes up which would
exacerbate a heating problem.

Being the parts are 35 years old they could have dried out and failed.
That
is why they have replacement parts.

Did you acquire it with the failed part or did it die on you? Good luck.

"Searcher7" <Search...@mail.con2.com> wrote in message

news:bd4ec732-92ee-4f0d-b4cf-9c8d1d3aae9c@eb1g2000vbb.googlegroups.com...







Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

I blew a capacitor on a game board I'm trying to get working and the
only culprits I can think of are the transformer assembly or the sub-
power assembly called the Regulator/Audio PCB, which does some audio
amplification, and some voltage regulation.

I'm still searching for technical information on how to test these
components, and if I can find out why the cap blew, perhaps it will
lead me to figuring out what I can't get the game to work.

http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuf...

Thanks.

Darren Harris
Staten Island, New York.
Click to expand...
There are three of those type of caps on the Millipede PCB. And yes
the board is from 1982.

I made an error in reading the info off the cap thanks to the dust,
but the info is as follows:
"ITT" "100.OU" "35.OS" "A x" "-40•85° C" (I'm just not sure if
the O's are really zeroes).

On my spare Millipede PCB it is the cap on the right:
http://i290.photobucket.com/albums/ll257/Statenislander/Arcade%20Stuff/MillipedePCBCapacitor.jpg

On another test point at just before the cap exploded I got a reading
of +24.94V. Was almost 3V over spec too high? (Perhaps that voltage in
combination with it being an old cap cause it to explode).

And should I replace the chipped regular in that image?

(I really have to learn how to read schematics).

Thanks a lot.

Darren Harris
Staten Island, New York.
 
On 2011-07-03, Searcher7 <Searcher7@mail.con2.com> wrote:
Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.
Click to expand...
tantalum capacitors can explode from spikes.

electrolytics can lose their polarisation and explode if used after
being left unused for several years, or sometimes it sesm that they
just explode spontaneously.

the dead part looks it it was a decoupling cap for the
7815 and the transistor opposite it. A 7815 is going to have aout 20
to 30V on it's input

If that's a date code on the black capacitor this game was assembled
around 1982 and may have been unused for several decades.

--
⚂⚃ 100% natural
 
On Jul 5, 3:29 am, Jasen Betts <ja...@xnet.co.nz> wrote:
On 2011-07-03,Searcher7<Search...@mail.con2.com> wrote:

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

tantalum capacitors can explode from spikes.

electrolytics can lose their polarisation and explode if used after
being left unused for several years, or sometimes it sesm that they
just explode spontaneously.

the dead part looks it it was a decoupling cap for the
7815 and the transistor opposite it. A 7815 is going to have aout 20
to 30V on it's input

If that's a date code on the black capacitor this game was assembled
around 1982 and may have been unused for several decades.

--
⚂⚃ 100% natural
Click to expand...
Thanks everyone.

I guess that on all the game boards I have that are not working I
should just replace all the capacitors. The boards on average are
about 30 years old.

Darren Harris
Staten Island, New York.
 
Searcher7 wrote:
On Jul 5, 3:29 am, Jasen Betts <ja...@xnet.co.nz> wrote:
On 2011-07-03,Searcher7<Search...@mail.con2.com> wrote:

Can voltage that is too low or transient spikes cause a capacitor to
explode? I'm not talking about capacitors that have dried out or are
not properly connected.

tantalum capacitors can explode from spikes.

electrolytics can lose their polarisation and explode if used after
being left unused for several years, or sometimes it sesm that they
just explode spontaneously.

the dead part looks it it was a decoupling cap for the
7815 and the transistor opposite it. A 7815 is going to have aout 20
to 30V on it's input

If that's a date code on the black capacitor this game was assembled
around 1982 and may have been unused for several decades.

Thanks everyone.

I guess that on all the game boards I have that are not working I
should just replace all the capacitors. The boards on average are
about 30 years old.

Electrolytics, yes definitely. Ceramics and mica caps, not so much;
Click to expand...
paper would be a judgement call, but it shouldn't cost an arm and a
leg to replace them with polyester or polypropylene.

Have Fun!
Rich
 
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