Solid caps can blow up?...

[Bertrand Sindri]

In sci.electronics.design Commander Kinsey <CK1@nospam.com> wrote:
> I didn\'t know solid caps could break.

Just about anything can be made to \"blow up\", provided one can find a
way to impart sufficient energy within a narrow enough time window.

This one shorted the 12V line on a graphics card, unfortunately I
have a 2.5kW supply,

So, one little cap, shorting, will dissapate something near, or greater
than, 2.5kW for the short time before it blows. 2.5kW of dissapation
in that tiny space is more than enough to cause significant damage,
including \"blowing up\".


Note - removed irrelevant windows groups from Newsgroups: header.

 

[Commander Kinsey]

On Tue, 09 Aug 2022 10:05:16 +0100, Paul <nospam@needed.invalid> wrote:

On 8/9/2022 2:17 AM, Commander Kinsey wrote:

I thought the ones in the photo were dry. What makes you think they\'re wet? I thought the wet ones were these kind with vents:
https://en.wikipedia.org/wiki/Capacitor_plague

Based on symptoms, there have been cases of capacitors
that needed vents, not getting vents. This was someones
attempt at capacitor fraud, selling cheap electrolytics
in polymer form-factor casings. (This was going on, early
in the intro of Polymer caps as a replacement for electrolytics.)

Companies do this, if they think they can\'t be sued.

Even on a decent thing like an AMD GPU?

When caps can fail on gas pressure, they have a K or an X
stamped in the metal top, to promote venting at sufficiently
high pressure. The rubber bung on the bottom can
also push out, as a relief mechanism, but is not the
preferred solution. It\'s better if the vent opens.

When the pH inside an electrolytic is wrong, it eats
through the K or X area and there is a stain on top.
The failed chemistry, even works without bias. The juice
can eat through in 1-2 years of sitting in the box.

*******

If intending to run a vid card at max power forever, it
pays to do a visual analysis and decide whether you want to
fit a third party cooler kit (with better surface blow-down
characteristics). In the year 2022 however, the picking are
slim, so this is no longer an option. One of the companies
good at making those, has stopped. And COVID was only one
factor in the decision. Even if you buy a water block kit, the
board might still need air cooling for the VRM section.

Most of them are not actually inside computer cases, they\'re sat loose on shelving, so they have a nice cool air intake. They\'re connected via USB extensions either to a PCI-Express slot, or a multiplexer to connect 4 into 1. It\'s the first time I\'ve had a failure there. I have blown some surface mount transistors on others, on the rear (non-fanned) side, in the power regulation area.

 

[Commander Kinsey]

On Tue, 09 Aug 2022 15:15:19 +0100, John Larkin <jjlarkin@highlandtechnology.com> wrote:

On Tue, 09 Aug 2022 05:45:17 +0100, \"Commander Kinsey\"
CK1@nospam.com> wrote:

On Tue, 09 Aug 2022 03:45:09 +0100, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

Commander Kinsey wrote:
On Tue, 09 Aug 2022 02:14:44 +0100, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

Commander Kinsey wrote:
I didn\'t know solid caps could break. This one shorted the 12V line on a
graphics card, unfortunately I have a 2.5kW supply, so the tracks got
damaged somewhat, it melted the solder, and ejected itself from the
board. Smelt of TCP (a disinfectant), presumably from the evaporated
paint?

https://imgur.com/jYet0zF

Gee, you forgot to cross-post to alt.scorekeeping.idiots and
rec.games.ropeadope.

What?

alt.comp.os.windows666 etc aren\'t super related to a computer repair
problem, I wouldn\'t have thought.

There are computer people in there.

Why does it concern you anyway? Just hit reply.

Inrush can kill any electrolytic capacitor. Some are more sensitive
than others.

It wasn\'t inrushing at the time. The card had been running without a
restart for a week or two. It\'s been running flat out 24/7 for the last
year doing astrophysics stuff on Boinc.

I\'ve never seen one of those break though, they\'re always the coloured
wet electrolytics that burst at the end and leak brown fluid.

Looks pretty wet to me.

What do you mean? If you\'re talking about the mess to the right, that\'s actually a piece of copper track for the ground that\'s burnt off the paint above it.

Sticking that right next to the (apparently
inadequately-sized, and certainly inadequately-vented) heat sink for the
SMPS switches isn\'t a recipe for long capacitor life.

Well it has to go somewhere, there\'s a lot of hot stuff on graphics cards. It also probably needs to be close to the other VRM stuff. Trouble is all these caps are also under the big heatsink for the main GPU which gives off up to 250W. That heatsink covers the whole card, there is nowhere cool.

Is this a gaming machine? Overclocked, overstressed, cheap, and
fundamentally useless?

I never overclock. They\'re used to run science applications. Boinc - a volunteer projects to run biology, astrophysics, etc.

 

[Commander Kinsey]

On Tue, 09 Aug 2022 15:32:25 +0100, Mr. Man-wai Chang <toylet.toylet@gmail.com> wrote:

On 9/8/2022 7:54 am, Commander Kinsey wrote:
I didn\'t know solid caps could break. This one shorted the 12V line on a graphics card, unfortunately I have a 2.5kW supply, so the tracks got damaged somewhat, it melted the solder, and ejected itself from the board. Smelt of TCP (a disinfectant), presumably from the evaporated paint?

https://imgur.com/jYet0zF

Should have posted to alt.comp.hardware.pc-homebuilt?

I wasn\'t aware of that group.

 

[Commander Kinsey]

On Tue, 09 Aug 2022 16:56:02 +0100, Marco Moock <mo01@posteo.de> wrote:

Am Dienstag, 09. August 2022, um 00:54:19 Uhr schrieb Commander Kinsey:

I didn\'t know solid caps could break.

Of course they can. They can also pop like normal caps.
In 2015 I tried putting water on a broken laptop motherboard just to
try out what happens - and one solid cap popped and flew through the
room.

I\'ve set fire to water. I watered a plant behind my 70s stereo amp while it was off and some got inside. Assuming it would have dried out when I used it next, I turned it on and received loud mains hum on the left, and music on the right. This was shortly followed by steam, then smoke, then flames inside the unit. About eleven components were destroyed so I gave up on it. I\'m guessing mains shorted into the amp input and everything overloaded?

 

[Commander Kinsey]

On Tue, 09 Aug 2022 21:10:00 +0100, Joerg <news@analogconsultants.com> wrote:

On 8/8/22 4:54 PM, Commander Kinsey wrote:
I didn\'t know solid caps could break. This one shorted the 12V line on a
graphics card, unfortunately I have a 2.5kW supply, so the tracks got
damaged somewhat, it melted the solder, and ejected itself from the
board. Smelt of TCP (a disinfectant), presumably from the evaporated paint?

https://imgur.com/jYet0zF

Regardless of how solid or less solid electrolytics are, they can and do
blow. Sometimes in a spectacular manner. As a kid I had a big one almost
the size of a coke can lift off and whizz by my right eye at less than
2\" distance. It hit the ceiling and took some plaster out of it, fell
back onto the carpet and smoldered a nasty burn into that.

I used to blow them up for a laugh, but outdoors. Many ended up in neighbour\'s gardens. The best was a 15V 53,000uF slightly bigger than a coke can cap. The bang caused ringing in my ears. There was no vent on that, until it created its own one.

You can get a nice smell off them if you blow up lots at once. I was an IT tech at a school where they were renovating and building an extension. Irish (ROFL) electricians confused the wiring colours from the old UK stuff and the new EU stuff and put 415V into a classroom instead of 240V. It was the woodwork department where they had three phase lathes, but also one phase computers, 20 per room. The power supplies in the old imacs didn\'t like 415V and simultaneously exploded, sending smoke everywhere. The teacher phoned me completely confused as to how so many computers would fail at the same time. The only thing that survived was a ceiling mounted projector I\'d installed myself, with a surge protector plug. The plug had become a pile of molten plastic, but protected the projector. I claimed on the electrician\'s new for old insurance policy, got 20 brand new computers, then replaced the caps in the old ones.

If the black ribbed thing is a heat sink and gets quite hot then the
placement of these caps so close to the heat sink was not a smart move
on the part of the design engineer for this board.

That\'s not what heats the caps. Above them (5mm away) is a 10 inch by 4 inch by 1 inch heatsink with two 80mm 5000rpm fans to cool a 250W GPU. I guess there is no cool place to put them.

 

[Commander Kinsey]

On Tue, 09 Aug 2022 21:34:50 +0100, Bertrand Sindri <bertrand.sindri@yahoo.com> wrote:

In sci.electronics.design Commander Kinsey <CK1@nospam.com> wrote:
I didn\'t know solid caps could break.

Just about anything can be made to \"blow up\", provided one can find a
way to impart sufficient energy within a narrow enough time window.

It chose to do this itself.

This one shorted the 12V line on a graphics card, unfortunately I
have a 2.5kW supply,

So, one little cap, shorting, will dissapate something near, or greater
than, 2.5kW for the short time before it blows. 2.5kW of dissapation
in that tiny space is more than enough to cause significant damage,
including \"blowing up\".

I have such a large supply as I have around 12 graphics cards all running at once. Easier to have one big 12V rail.

The input to my house currently reads 243V, 26.4A.

I\'m hoping to repair it....

 

[Bertrand Sindri]

Commander Kinsey <CK1@nospam.com> wrote:

On Tue, 09 Aug 2022 21:34:50 +0100, Bertrand Sindri <bertrand.sindri@yahoo.com> wrote:

In sci.electronics.design Commander Kinsey <CK1@nospam.com> wrote:
I didn\'t know solid caps could break.

Just about anything can be made to \"blow up\", provided one can find a
way to impart sufficient energy within a narrow enough time window.

It chose to do this itself.

It (the capacitor) made no such choice, as it lacks consciousness with
which to do so.

Instead, wear and tear, likely heat related, resulted in it eventually
shorting. And once it shorted, it then dissapated sufficient energy
within a narrow enough time window to blow up.

 

[T]

On 8/9/22 12:09, rbowman wrote:

On 08/09/2022 04:04 AM, T wrote:
On 8/8/22 16:54, Commander Kinsey wrote:
I didn\'t know solid caps could break. This one shorted the 12V line on
a graphics card, unfortunately I have a 2.5kW supply, so the tracks
got damaged somewhat, it melted the solder, and ejected itself from
the board. Smelt of TCP (a disinfectant), presumably from the
evaporated paint?

https://imgur.com/jYet0zF

By chance, was it in backwards?

Those tend to be infantile failures.

True. I have seen a few make it awhile,
but it is very unusual.

I saw \"16V\" on the top. If it is facing
12V, then it is not much of an over rating.
But it might be facing 5V.

It could also be \"poop happens\".

2.KW power supply. Is he arc welding with it?

 

[Commander Kinsey]

On Tue, 09 Aug 2022 22:08:30 +0100, Bertrand Sindri <bertrand.sindri@yahoo.com> wrote:

Commander Kinsey <CK1@nospam.com> wrote:
On Tue, 09 Aug 2022 21:34:50 +0100, Bertrand Sindri <bertrand.sindri@yahoo.com> wrote:

In sci.electronics.design Commander Kinsey <CK1@nospam.com> wrote:
I didn\'t know solid caps could break.

Just about anything can be made to \"blow up\", provided one can find a
way to impart sufficient energy within a narrow enough time window.

It chose to do this itself.

It (the capacitor) made no such choice, as it lacks consciousness with
which to do so.

Instead, wear and tear, likely heat related, resulted in it eventually
shorting. And once it shorted, it then dissapated sufficient energy
within a narrow enough time window to blow up.

The choice then was made by the designer who cut corners and didn\'t care if it exploded after 10 years, since it only has a warranty for 2 or 3.

The worst one I saw was a compact fluorescent animal UV lamp from China. The capacitor burst after 3 months use. So I put in a bigger one (higher voltage and low ESD). It seems to be happy now. Still, it was £7..50 for the lamp and the proper ones from big companies are £20-£30, which I\'ve also had fail. Again, heat. Almost an absolute lack of vents on the chassis.

 

[Paul]

On 8/9/2022 4:47 PM, Commander Kinsey wrote:

That\'s not what heats the caps.  Above them (5mm away) is a
10 inch by 4 inch by 1 inch heatsink with two 80mm 5000rpm
fans to cool a 250W GPU.  I guess there is no cool place to put them.

What I don\'t like about that area, as a co-factor, is
two connectors carrying a lot of amperes for the +12V
and the board is probably using half ounce copper.
It could be that a track traveling near the capacitor,
contributed to the local heating effects. Sometimes, the
exit area near the connectors needs via-stitching to
try to spread the current better into the departing
power tracks or power plane.

If it died purely on ripple current, you\'d expect its
neighbors to be showing signs of that too.

But when everything is a blackened mess like that, it\'s
pretty hard to see everything. Either that black is PCB
charring, or it\'s chemical attack from whatever passed
as a liquid in the cap. Charred PCB might be more brownish
than black tar colored.

The pattern suggests it may have vented, down low.
Like maybe a hole burned in the cap, or the seal on
the bottom releasing under pressure.

Paul

 

[Commander Kinsey]

On Tue, 09 Aug 2022 22:53:36 +0100, Paul <nospam@needed.invalid> wrote:

On 8/9/2022 4:47 PM, Commander Kinsey wrote:

That\'s not what heats the caps. Above them (5mm away) is a
10 inch by 4 inch by 1 inch heatsink with two 80mm 5000rpm
fans to cool a 250W GPU. I guess there is no cool place to put them.

What I don\'t like about that area, as a co-factor, is
two connectors carrying a lot of amperes for the +12V
and the board is probably using half ounce copper.
It could be that a track traveling near the capacitor,
contributed to the local heating effects. Sometimes, the
exit area near the connectors needs via-stitching to
try to spread the current better into the departing
power tracks or power plane.

Yes, the current in those cards is absurd. Hence the use of 12V instead of the 1V for the GPU chip. Maybe they should switch to something higher than 12V?

If it died purely on ripple current, you\'d expect its
neighbors to be showing signs of that too.

Do they show gradual signs or just a sudden pop?

But when everything is a blackened mess like that, it\'s
pretty hard to see everything. Either that black is PCB
charring, or it\'s chemical attack from whatever passed
as a liquid in the cap. Charred PCB might be more brownish
than black tar colored.

There was a very strong smell of TCP (normally a disinfectant) when it did it. The area next to it is a copper track, now no longer attached to the board, about 1cm squared which has no sign of blue paint left above it. I assume the paint burnt off.

The pattern suggests it may have vented, down low.
Like maybe a hole burned in the cap, or the seal on
the bottom releasing under pressure.

Not sure where all the carbon came from. Under the capacitor are only minor signs much came out the bottom.

 

[Paul]

On 8/9/2022 9:07 AM, Mayayana wrote:

\"Paul\" <nospam@needed.invalid> wrote

| > https://imgur.com/jYet0zF
|

Here\'s the real link without the imgur BS:
https://i.imgur.com/jYet0zF.jpg

I once had a case where one of those blew up.
I was putting in a CD player. Apparently there was
a short somewhere inside the player. I smelled electrical
fire, but before I could do anything it blew up, taking
all the components f the computer with it. Everything
got fried.

That could be a +5V shorted to +12V fault. I could
see that blowing all the +5V logic.

Paul

 

[Paul]

On 8/9/2022 5:41 PM, T wrote:

On 8/9/22 12:09, rbowman wrote:
On 08/09/2022 04:04 AM, T wrote:
On 8/8/22 16:54, Commander Kinsey wrote:
I didn\'t know solid caps could break. This one shorted the 12V line on
a graphics card, unfortunately I have a 2.5kW supply, so the tracks
got damaged somewhat, it melted the solder, and ejected itself from
the board. Smelt of TCP (a disinfectant), presumably from the
evaporated paint?

https://imgur.com/jYet0zF

By chance, was it in backwards?

Those tend to be infantile failures.


True.  I have seen a few make it awhile,
but it is very unusual.

I saw \"16V\" on the top.  If it is facing
12V, then it is not much of an over rating.
But it might be facing 5V.

It could also be \"poop happens\".

2.KW power supply.  Is he arc welding with it?

When you\'re doing this, you can share a big supply across multiple cards.

https://lolminer.site/assets/images/mining/mining_rig_1006.jpg

The OPs setup is not neat and tidy like that.

Paul

 

[T]

On 8/9/22 15:47, Paul wrote:

When you\'re doing this, you can share a big supply across multiple cards.

https://lolminer.site/assets/images/mining/mining_rig_1006.jpg

I have a crypto currency customer that has
one of these. A super computer using the
GPU\'s as parallel processors. The CPU does
hardly anything.

 

[legg]

On Tue, 09 Aug 2022 00:54:19 +0100, \"Commander Kinsey\"
<CK1@nospam.com> wrote:

I didn\'t know solid caps could break. This one shorted the 12V line on a graphics card, unfortunately I have a 2.5kW supply, so the tracks got damaged somewhat, it melted the solder, and ejected itself from the board. Smelt of TCP (a disinfectant), presumably from the evaporated paint?

https://imgur.com/jYet0zF

There\'s no evidence that the cap was the first part to fail,
or by what means.

The flammability of these parts or their contents can\'t be
considered as anything better than \'will not sustain open
flame\' - but they\'ll burn if subjected to sufficient temperature
and energy, as will FR4 printed wiring.

RL

 

[Commander Kinsey]

On Wed, 10 Aug 2022 02:15:59 +0100, legg <legg@nospam.magma.ca> wrote:

On Tue, 09 Aug 2022 00:54:19 +0100, \"Commander Kinsey\"
CK1@nospam.com> wrote:

I didn\'t know solid caps could break. This one shorted the 12V line on a graphics card, unfortunately I have a 2.5kW supply, so the tracks got damaged somewhat, it melted the solder, and ejected itself from the board. Smelt of TCP (a disinfectant), presumably from the evaporated paint?

https://imgur.com/jYet0zF

There\'s no evidence that the cap was the first part to fail,
or by what means.

The flammability of these parts or their contents can\'t be
considered as anything better than \'will not sustain open
flame\' - but they\'ll burn if subjected to sufficient temperature
and energy, as will FR4 printed wiring.

Must be better than 70s stuff, I had a stereo amp catch fire inside, and it sustained the flame for 20 seconds before I blew it out.

 

[Brian Gregory]

On 09/08/2022 16:56, Marco Moock wrote:

Am Dienstag, 09. August 2022, um 00:54:19 Uhr schrieb Commander Kinsey:

I didn\'t know solid caps could break.

Of course they can. They can also pop like normal caps.
In 2015 I tried putting water on a broken laptop motherboard just to
try out what happens - and one solid cap popped and flew through the
room.

Just from water?
That\'s hard to believe.

--
Brian Gregory (in England).

 

[Commander Kinsey]

On Wed, 10 Aug 2022 03:07:19 +0100, Brian Gregory <void-invalid-dead-dontuse@email.invalid> wrote:

On 09/08/2022 16:56, Marco Moock wrote:
Am Dienstag, 09. August 2022, um 00:54:19 Uhr schrieb Commander Kinsey:

I didn\'t know solid caps could break.

Of course they can. They can also pop like normal caps.
In 2015 I tried putting water on a broken laptop motherboard just to
try out what happens - and one solid cap popped and flew through the
room.


Just from water?
That\'s hard to believe.

It worked for my stereo. I guess if water conducts a bit in one part of the circuit, everything goes out of whack.

 

[New Me]

On 10/08/2022 03:07, Brian Gregory wrote:

On 09/08/2022 16:56, Marco Moock wrote:
Am Dienstag, 09. August 2022, um 00:54:19 Uhr schrieb Commander Kinsey:

I didn\'t know solid caps could break.

Of course they can. They can also pop like normal caps.
In 2015 I tried putting water on a broken laptop motherboard just to
try out what happens - and one solid cap popped and flew through the
room.


Just from water?
That\'s hard to believe.

That\'s hard to believe for sure. I wash my desktop\'s motherboard with
water every 12 months and there is no malfunction after cleaning
and drying it throughly. Machine is still as fast as it was when I
bought it 5 years ago.