Caps loadly popping on motherboard

M

Michael C

Guest
I've got a motherboard that runs off a single 12V supply (Via ITX board). It
provides power to the hdd and cd-rom via a power out plug. I hooked it up
today with a 12V supply and shortly after starting it up one of the caps in
the onboard power supply popped quite loudly. Then a minute or so later
another one popped. I was only running a single hdd and no CD rom so
wouldn't have thought I was overpowering it. Can anyone tell me what is
likely to have happened?

Thanks,
Michael
 
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX board).
It provides power to the hdd and cd-rom via a power out plug. I hooked it
up today with a 12V supply and shortly after starting it up one of the
caps in the onboard power supply popped quite loudly. Then a minute or so
later another one popped. I was only running a single hdd and no CD rom so
wouldn't have thought I was overpowering it. Can anyone tell me what is
likely to have happened?
Click to expand...
You'd think I would have learnt how to spell loud by now :)

Michael
 
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX board).
It provides power to the hdd and cd-rom via a power out plug. I hooked it
up today with a 12V supply and shortly after starting it up one of the
caps in the onboard power supply popped quite loudly. Then a minute or so
later another one popped. I was only running a single hdd and no CD rom so
wouldn't have thought I was overpowering it. Can anyone tell me what is
likely to have happened?
Click to expand...
**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
 
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX board).
It provides power to the hdd and cd-rom via a power out plug. I hooked it
up today with a 12V supply and shortly after starting it up one of the
caps in the onboard power supply popped quite loudly. Then a minute or so
later another one popped. I was only running a single hdd and no CD rom
so wouldn't have thought I was overpowering it. Can anyone tell me what
is likely to have happened?

**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
Click to expand...
 
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...

"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug. I
hooked it up today with a 12V supply and shortly after starting it up
one of the caps in the onboard power supply popped quite loudly. Then a
minute or so later another one popped. I was only running a single hdd
and no CD rom so wouldn't have thought I was overpowering it. Can anyone
tell me what is likely to have happened?

**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
Click to expand...
**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
 
Trevor Wilson wrote:

Polarity?

**Good point, though I doubt anyone could be THAT stupid.
Click to expand...
So this is an offer to better that? I'll bite. :)

A small "Squirrel" printer used in POS applications come in for repair.
Report said "Dead". Apon closer inspection and preparation to apply 12v to
power up the unit, we notice the PCB is completely cooked. Nothing that a
mere 12v could do, this needed more juice than that. Turns out client lost
the adaptor for one of these things, and made up their own - by plugging it
into the mains.
--
Linux Registered User # 302622
<http://counter.li.org>
 
"John Tserkezis" <jt@techniciansyndrome.org.invalid> wrote in message
news:475721e8$0$13919$afc38c87@news.optusnet.com.au...
Trevor Wilson wrote:

Polarity?

**Good point, though I doubt anyone could be THAT stupid.

So this is an offer to better that? I'll bite. :)

A small "Squirrel" printer used in POS applications come in for repair.
Report said "Dead". Apon closer inspection and preparation to apply 12v
to power up the unit, we notice the PCB is completely cooked. Nothing
that a mere 12v could do, this needed more juice than that. Turns out
client lost the adaptor for one of these things, and made up their own -
by plugging it into the mains.
Click to expand...
**That's pretty good. I have photos (somewhere) of a turntable, where the
client accidentally wired the phono leads to the mains supply......

The headshell was one of those plastic ones and arrived as a blob on the end
of the tone arm. It was a beaut. The other one (which I also have photos of)
is where a client's wife/girlfriend arrived home early, to find my client in
bed with another woman. She grabbed a hammer and took to his hi fi system.

Hell hath no fury and all that.

I'll try to locate the pics, scan and post them somewhere.

Trevor Wilson
 
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...

"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...

"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug. I
hooked it up today with a 12V supply and shortly after starting it up
one of the caps in the onboard power supply popped quite loudly. Then a
minute or so later another one popped. I was only running a single hdd
and no CD rom so wouldn't have thought I was overpowering it. Can
anyone tell me what is likely to have happened?

**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?

**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
A million years ago, or thereabouts, I bought a single-board computer,
Click to expand...
called AIM65. Based on a 6502 chip. It needed a power supply that provided,
I think, +5, and +24 volts. I was dead tired, and it was about 1:00AM, and I
was wiring and soldering a breadboard rat's nest of a temporary power supply
, sitting on the floor. I fired up the finished supply, and it didn't work.
I bent over it to look at what was wrong, and a big electrolytic (about the
size of a D cell) exploded and shot past my head and made a big dent in the
ceiling which is still there. It could have blinded me. I had wired it back
to front.
Yes, some of us are THAT stupid. Sometimes.
 
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...

"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...

"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug. I
hooked it up today with a 12V supply and shortly after starting it up
one of the caps in the onboard power supply popped quite loudly. Then a
minute or so later another one popped. I was only running a single hdd
and no CD rom so wouldn't have thought I was overpowering it. Can
anyone tell me what is likely to have happened?

**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?

**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
Yes, well... We can all be stupid at times. Recently I had to cut the output
Click to expand...
wires of an *AC* plugpack. Then I spent a fruitless couple of hours trying
to determine what polarity was each lead...
<g>
 
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:AYF5j.20731$CN4.16315@news-server.bigpond.net.au...
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...

"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...

"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...

"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug.
I hooked it up today with a 12V supply and shortly after starting it
up one of the caps in the onboard power supply popped quite loudly.
Then a minute or so later another one popped. I was only running a
single hdd and no CD rom so wouldn't have thought I was overpowering
it. Can anyone tell me what is likely to have happened?

**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?

**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
A million years ago, or thereabouts, I bought a single-board computer,
called AIM65. Based on a 6502 chip. It needed a power supply that
provided, I think, +5, and +24 volts. I was dead tired, and it was about
1:00AM, and I was wiring and soldering a breadboard rat's nest of a
temporary power supply , sitting on the floor. I fired up the finished
supply, and it didn't work. I bent over it to look at what was wrong, and
a big electrolytic (about the size of a D cell) exploded and shot past my
head and made a big dent in the ceiling which is still there. It could
have blinded me. I had wired it back to front.
Yes, some of us are THAT stupid. Sometimes.

Sometime back another young poster to this NG had a similar experience with
Click to expand...
an exploding electrolytic.
Difference was it hit him square in the forehead, leaving a crosshair
pattern resembling the vent release on the top of the cap.
Lucky he didn't cop it in an eye !

Cheers,
Alan
 
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
Click to expand...
Yep, measured at 12V and polarity is correct, positive in the centre like
most of em. It's the same brand and model I have used previously. Possible
it's faulty somehow?

Michael
 
On 6/12/2007 13:11 Alan Rutlidge wrote:
Sometime back another young poster to this NG had a similar experience with
an exploding electrolytic.
Difference was it hit him square in the forehead, leaving a crosshair
pattern resembling the vent release on the top of the cap.
Lucky he didn't cop it in an eye !

Cheers,
Alan
Click to expand...
I installed a 10uF electrolytic backwards in an amp I was repairing
once. It was a bypass cap on an STK package.
There was a very loud bang as I was leaning over the unit, and the
cap's can flew past my face, missing my eye by maybe an inch before
hitting the ceiling then bouncing around the room.
Nice to know I'm not the only one's who done that. :)

Bob
 
Trevor Wilson wrote:
"John Tserkezis" <jt@techniciansyndrome.org.invalid> wrote in message
news:475721e8$0$13919$afc38c87@news.optusnet.com.au...
Trevor Wilson wrote:

Polarity?
**Good point, though I doubt anyone could be THAT stupid.
So this is an offer to better that? I'll bite. :)

A small "Squirrel" printer used in POS applications come in for repair.
Report said "Dead". Apon closer inspection and preparation to apply 12v
to power up the unit, we notice the PCB is completely cooked. Nothing
that a mere 12v could do, this needed more juice than that. Turns out
client lost the adaptor for one of these things, and made up their own -
by plugging it into the mains.

**That's pretty good. I have photos (somewhere) of a turntable, where the
client accidentally wired the phono leads to the mains supply......

The headshell was one of those plastic ones and arrived as a blob on the end
of the tone arm. It was a beaut. The other one (which I also have photos of)
is where a client's wife/girlfriend arrived home early, to find my client in
bed with another woman. She grabbed a hammer and took to his hi fi system.

Hell hath no fury and all that.

I'll try to locate the pics, scan and post them somewhere.

Trevor Wilson
Click to expand...
Best one I heard was a friends sister was using a handheld cake mixer
when the mains lead somehow worked loose and fell into the cake mix.
Without thinking she picked up the leads and licked the cake mix of them
and got one hell of a boot on her tongue.

Dorf
 
Suzy wrote:
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug. I
hooked it up today with a 12V supply and shortly after starting it up
one of the caps in the onboard power supply popped quite loudly. Then a
minute or so later another one popped. I was only running a single hdd
and no CD rom so wouldn't have thought I was overpowering it. Can
anyone tell me what is likely to have happened?
**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
Yes, well... We can all be stupid at times. Recently I had to cut the output
wires of an *AC* plugpack. Then I spent a fruitless couple of hours trying
to determine what polarity was each lead...
g
Click to expand...
So did you get it right in the end?

Dorf
 
A looooong time ago I used to work on welding machines
at a manufacturer, and hooked up the enormous ~20 x 10cm dia.
Mallory can electrolytic used on the rectified output of the
DC MIG welding output section backwards...

The sides were open on the machine in production,
luckily I was standing just behind the rear plate when I
powered it up (415V 3 phase too)...
The cap blew like a grenade, exploding its guts everywhere
with a bang and force that scared the absolute shit out of
me and everyone else in the factory.

Took me a while to clean up the inside of that machine and
all around :)

Since then and a smaller occasion (not backwards cap)
I always wear safety glasses when powering up a suspicious
or repaired power supply or other device with electro's
and high current supply, don't want to lose an eye either...
My safety glasses sit on the shelf just above the workbench.
I've had tantalum caps throw burning shards around too.


--
Cheers,

Marc

* My email address requires the identical words and
* underscores removed to email me

"Bob Parker" <bobp.deletethis@bluebottle.com> wrote in message
news:47577ed4$0$22949$5a62ac22@per-qv1-newsreader-01.iinet.net.au...
On 6/12/2007 13:11 Alan Rutlidge wrote:

Sometime back another young poster to this NG had a similar experience
with an exploding electrolytic.
Difference was it hit him square in the forehead, leaving a crosshair
pattern resembling the vent release on the top of the cap.
Lucky he didn't cop it in an eye !

Cheers,
Alan


I installed a 10uF electrolytic backwards in an amp I was repairing
once. It was a bypass cap on an STK package.
There was a very loud bang as I was leaning over the unit, and the
cap's can flew past my face, missing my eye by maybe an inch before
hitting the ceiling then bouncing around the room.
Nice to know I'm not the only one's who done that. :)

Bob
Click to expand...
 
"Dorfus" <Dorfus.Dippintush@kippinbot.com> wrote in message
news:4757e4b0_1@news.peopletelecom.com.au...
Suzy wrote:
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug.
I hooked it up today with a 12V supply and shortly after starting it
up one of the caps in the onboard power supply popped quite loudly.
Then a minute or so later another one popped. I was only running a
single hdd and no CD rom so wouldn't have thought I was overpowering
it. Can anyone tell me what is likely to have happened?
**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
Yes, well... We can all be stupid at times. Recently I had to cut the
output wires of an *AC* plugpack. Then I spent a fruitless couple of
hours trying to determine what polarity was each lead...
g

So did you get it right in the end?

Dorf
Click to expand...
Yes, I managed to identify the polarity in a 50th of a second, although it
changed immediately afterwards, but it's OK because it changed back again...
 
On Wed, 5 Dec 2007 22:01:22 +1100, "Michael C" <nospam@nospam.com> put
finger to keyboard and composed:

I've got a motherboard that runs off a single 12V supply (Via ITX board). It
provides power to the hdd and cd-rom via a power out plug. I hooked it up
today with a 12V supply and shortly after starting it up one of the caps in
the onboard power supply popped quite loudly. Then a minute or so later
another one popped. I was only running a single hdd and no CD rom so
wouldn't have thought I was overpowering it. Can anyone tell me what is
likely to have happened?

Thanks,
Michael
Click to expand...
The caps in the onboard PSU are probably 6.3V types. Maybe the PSU
failed in such a way that the input voltage was shorting to the output
??? I've never tried powering a motherboard without a CPU, but could
doing so bring about such a failure ???

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
Suzy wrote:
"Dorfus" <Dorfus.Dippintush@kippinbot.com> wrote in message
news:4757e4b0_1@news.peopletelecom.com.au...
Suzy wrote:
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out plug.
I hooked it up today with a 12V supply and shortly after starting it
up one of the caps in the onboard power supply popped quite loudly.
Then a minute or so later another one popped. I was only running a
single hdd and no CD rom so wouldn't have thought I was overpowering
it. Can anyone tell me what is likely to have happened?
**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
Yes, well... We can all be stupid at times. Recently I had to cut the
output wires of an *AC* plugpack. Then I spent a fruitless couple of
hours trying to determine what polarity was each lead...
g
So did you get it right in the end?

Dorf

Yes, I managed to identify the polarity in a 50th of a second, although it
changed immediately afterwards, but it's OK because it changed back again...
Click to expand...
Thank goodness for that!

What are you working on lately Suzy? You're always doing interesting
things. Did you design an antenna?

Dorf
 
"Dorfus" <Dorfus.Dippintush@kippinbot.com> wrote in message
news:475863a4_8@news.peopletelecom.com.au...
Suzy wrote:
"Dorfus" <Dorfus.Dippintush@kippinbot.com> wrote in message
news:4757e4b0_1@news.peopletelecom.com.au...
Suzy wrote:
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rok0aF15nmntU1@mid.individual.net...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5rodm1F15emfvU1@mid.individual.net...
"Michael C" <nospam@nospam.com> wrote in message
news:4756847c$0$9878$afc38c87@news.optusnet.com.au...
I've got a motherboard that runs off a single 12V supply (Via ITX
board). It provides power to the hdd and cd-rom via a power out
plug. I hooked it up today with a 12V supply and shortly after
starting it up one of the caps in the onboard power supply popped
quite loudly. Then a minute or so later another one popped. I was
only running a single hdd and no CD rom so wouldn't have thought I
was overpowering it. Can anyone tell me what is likely to have
happened?
**It wasn't really a 12 Volt supply?

Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?
**Good point, though I doubt anyone could be THAT stupid.

Trevor Wilson
Yes, well... We can all be stupid at times. Recently I had to cut the
output wires of an *AC* plugpack. Then I spent a fruitless couple of
hours trying to determine what polarity was each lead...
g
So did you get it right in the end?

Dorf

Yes, I managed to identify the polarity in a 50th of a second, although
it changed immediately afterwards, but it's OK because it changed back
again...

Thank goodness for that!

What are you working on lately Suzy? You're always doing interesting
things. Did you design an antenna?

Dorf
Click to expand...
Yes, it receives its own transmissions, so lessening spectrum congestion,
not to mention propagation delay...
 
"Michael C" <mculleyNOSPAM@optushome.com.au> wrote in message
news:4757d91b$0$14416$afc38c87@news.optusnet.com.au...
"L.A.T." <tonyt92@yahoo.com> wrote in message
news:nvE5j.20683$CN4.12187@news-server.bigpond.net.au...
Did you measure the "12 Volt supply"?

Trevor Wilson
Polarity?

Yep, measured at 12V and polarity is correct, positive in the centre like
most of em. It's the same brand and model I have used previously. Possible
it's faulty somehow?
Click to expand...
**What Voltage were the exploding caps rated for?
What Voltage did you measure on the supply?

Trevor Wilson
 
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