4 pin 12v atx power supply connected the wrong way...

M

Mike Henley

Hi... thanks to a distraction i ended up connecting the 4 pin 12v atx
power supply from the psu to the motherboard\cpu the wrong way... it
was a 180 the wrong way... it sounded like a firecracker when i turned
on the machine and it went dead.... everything else was connected
right just that one stupid 4 pin 12v...

what might've got damaged... would the motherboard only got
damaged.... or the motherboard and cpu too... would other parts i had
connected like memory, graphics card, hdd etc damaged too... thanks

(it's an amd athlon 64 and asus k8v) :-(
 
K

kony

Hi... thanks to a distraction i ended up connecting the 4 pin 12v atx
power supply from the psu to the motherboard\cpu the wrong way... it
was a 180 the wrong way... it sounded like a firecracker when i turned
on the machine and it went dead.... everything else was connected
right just that one stupid 4 pin 12v...

what might've got damaged... would the motherboard only got
damaged.... or the motherboard and cpu too... would other parts i had
connected like memory, graphics card, hdd etc damaged too... thanks

(it's an amd athlon 64 and asus k8v) :-(

If the power supply meets the Intel ATX12V guidlines it should have turned
off and not be damaged. If it's a cheap/generic power supply then all
bets are off. The motherboard should be dead but most likely nothing
else.
 
G

General Schvantzkoph

Hi... thanks to a distraction i ended up connecting the 4 pin 12v atx
power supply from the psu to the motherboard\cpu the wrong way... it
was a 180 the wrong way... it sounded like a firecracker when i turned
on the machine and it went dead.... everything else was connected
right just that one stupid 4 pin 12v...

what might've got damaged... would the motherboard only got
damaged.... or the motherboard and cpu too... would other parts i had
connected like memory, graphics card, hdd etc damaged too... thanks

(it's an amd athlon 64 and asus k8v) :-(

Look for burned components on the motherboard. The firecraker sound was
most probably a capacitor blowing up. The motherboard is probably toast.
If the DC to DC converter went it might have taken the CPU with it, but
there is a good chance that the converter sacrificed itself and didn't
take the CPU with it. Your RAM is probably OK but if -12 volts passed
through the CPU it could have taken out the RAM also. The graphics card is
on the otherside of the bridge chip so I suspect that that's OK unless the
AGP slot gets power from the 4 pin 12V connector. The disk and CDROM will
be fine if that's any comfort.

BTW isn't the 4 pin connector keyed? I would have thought that it would be
impossible to do what you did.
 
P

philo

Mike Henley said:
Hi... thanks to a distraction i ended up connecting the 4 pin 12v atx
power supply from the psu to the motherboard\cpu the wrong way... it
was a 180 the wrong way... it sounded like a firecracker when i turned
on the machine and it went dead.... everything else was connected
right just that one stupid 4 pin 12v...

what might've got damaged... would the motherboard only got
damaged.... or the motherboard and cpu too... would other parts i had
connected like memory, graphics card, hdd etc damaged too... thanks

(it's an amd athlon 64 and asus k8v) :-(


how did you do that...i thought they were keyed?
 
M

Mike Henley

philo said:
how did you do that...i thought they were keyed?

i thought so... that's why i didn't think twice about it once it
slipped in and seemed to fit... on a previous motherboard there was
only one way to connect a 4pin connector and that was the right way...
on this asus k8v it seemed to fit in both the right way and the wrong
way... i don't think it's the psu's fault... i think the thing on the
motherboard is probably keyed too wide...
 
M

Mike Henley

kony said:
If the power supply meets the Intel ATX12V guidlines it should have turned
off and not be damaged. If it's a cheap/generic power supply then all
bets are off. The motherboard should be dead but most likely nothing
else.

okay... i used another PSU that i had... strangely it didn't work...
but then when i used another power cable (from mains to psu) with that
other PSU it worked... the machine ran perfectly, i formatted the HD,
installed windows... everything was fine and perfect... so i came to
the conclusion it was a 5a fuse on that cable that got damaged... till
i decided to test the other PSU with the working mains-psu power cable
('cos it was a good psu)... it didn't work, and not only that, but
when i tried to put back the working psu it didn't work either!...
eventhough i connected it with the working cable... now i'm gonna go
and buy some 5a fuses...

i don't know if this will work... this is strange... but i was
relieved and happy when the computer ran and i was able to run windows
 
K

kony

okay... i used another PSU that i had... strangely it didn't work...
but then when i used another power cable (from mains to psu) with that
other PSU it worked... the machine ran perfectly, i formatted the HD,
installed windows... everything was fine and perfect... so i came to
the conclusion it was a 5a fuse on that cable that got damaged...

??? A "normal" AC power supply cable has no fuse in it at all, just a
straight pin-to-pin connection. If you have a multimeter you might check
the continuity, or rather, resistance of the conductors.

...till
i decided to test the other PSU with the working mains-psu power cable
('cos it was a good psu)... it didn't work, and not only that, but
when i tried to put back the working psu it didn't work either!...
eventhough i connected it with the working cable... now i'm gonna go
and buy some 5a fuses...

Normally a closed circuit short on a power supply will turn it off but not
blow the fuse, if you're meaning the internal fuse, not a ? (cord fuse).
Again this assumes it meets ATX12V guidlines, not missing essential safety
features.

It's curious that you're having this intermittent success... perhaps the
power supply or motherboard 4-pin connector is stress damaged or burnt,
making bad contact.

i don't know if this will work... this is strange... but i was
relieved and happy when the computer ran and i was able to run windows

That firecracker sound you reported is troubling, something is likely
damaged and ought to be isolated and repaired or replaced before the
system is powered up again. A fuse blowing makes little to no noise.
 
G

General Schvantzkoph

That firecracker sound you reported is troubling, something is likely
damaged and ought to be isolated and repaired or replaced before the
system is powered up again. A fuse blowing makes little to no noise.

Fuses don't make any noise when they blow but capacitors do. If the cap
was on the motherboard it will be obvious, look for a scorch mark. The cap
might be inside the power supply in which case you'll have to take the
supply apart to find it (I wouldn't bother, I'd just dump that supply in
the trash).
 
M

Mike Henley

kony said:
??? A "normal" AC power supply cable has no fuse in it at all, just a
straight pin-to-pin connection. If you have a multimeter you might check
the continuity, or rather, resistance of the conductors.



Normally a closed circuit short on a power supply will turn it off but not
blow the fuse, if you're meaning the internal fuse, not a ? (cord fuse).
Again this assumes it meets ATX12V guidlines, not missing essential safety
features.

It's curious that you're having this intermittent success... perhaps the
power supply or motherboard 4-pin connector is stress damaged or burnt,
making bad contact.



That firecracker sound you reported is troubling, something is likely
damaged and ought to be isolated and repaired or replaced before the
system is powered up again. A fuse blowing makes little to no noise.

Okay... i've been to the store, i got some 5a fuses... so here's the
story... i replaced the fuse in the good PSU's power cable (mains to
PSU) and it worked... the computer is running fine, i downloaded video
from a cam, installed apps, everything is more or less running just
fine with no problem...

then that PSU that was connected when i had the accident (the
firecracker sound)... well, i replaced the fuse in its cable (mains to
PSU cable)... and it didn't run... maybe the firecracker sound came
from the PSU after all... i don't know... but that PSU isn't working
now... it was a high-end 550w PSU... i'm sorry it blew up 'cos it was
pricey but i'm sorta glad it sacrificed itself...

i find it strange that you say a normal cable doesn't have a fuse...
'cos i have those two PSUs and 3 cables... i can't remember which is
which... two of them are 5amp-fused, one is not... as mentioned above
about two fused ones, in addition, the unfused one gave me a nasty
spark when i plugged it in so i gave up on it... i was lucky that it
was the faulty psu that was connected rather than the good one when
that happened... so, i decided i won't be using the unfused cable
again.
 
K

kony

Okay... i've been to the store, i got some 5a fuses... so here's the
story... i replaced the fuse in the good PSU's power cable (mains to
PSU) and it worked... the computer is running fine, i downloaded video
from a cam, installed apps, everything is more or less running just
fine with no problem...

This still makes no sense... your (AC wall outlet to power supply) cords
have fuses? I've seen cords with fuses, but never for a PC power supply.
then that PSU that was connected when i had the accident (the
firecracker sound)... well, i replaced the fuse in its cable (mains to
PSU cable)... and it didn't run... maybe the firecracker sound came
from the PSU after all... i don't know... but that PSU isn't working
now... it was a high-end 550w PSU... i'm sorry it blew up 'cos it was
pricey but i'm sorta glad it sacrificed itself...

What brand was the 550W?
If you leave it disconnected from AC for a few minutes and open it, you
may see the damage. If a cap blew up you might see some paper-like foil
loose in the casing, if the damaged cap isn't intact enough to be
identifiable.
i find it strange that you say a normal cable doesn't have a fuse...
'cos i have those two PSUs and 3 cables... i can't remember which is
which... two of them are 5amp-fused, one is not... as mentioned above
about two fused ones, in addition, the unfused one gave me a nasty
spark when i plugged it in so i gave up on it... i was lucky that it
was the faulty psu that was connected rather than the good one when
that happened... so, i decided i won't be using the unfused cable
again.

There might have been something wrong with the power supply to begin with,
it shouldn't be drawing more than a fraction of an amp before the system
is powered on.
 
N

Noozer

kony said:
This still makes no sense... your (AC wall outlet to power supply) cords
have fuses? I've seen cords with fuses, but never for a PC power supply.

Very possibly... what country is the original poster located in?

<snip>
 
M

Mike Henley

kony said:
This still makes no sense... your (AC wall outlet to power supply) cords
have fuses? I've seen cords with fuses, but never for a PC power supply.

I have those fused wires and this unfused one... i'm not sure which
belongs to which... but what i reported is how it happened...
What brand was the 550W?
If you leave it disconnected from AC for a few minutes and open it, you
may see the damage. If a cap blew up you might see some paper-like foil
loose in the casing, if the damaged cap isn't intact enough to be
identifiable.

It's vantec stealth 520w... a pretty nice one... i won't be opening
'cos it has a sticker that says warranty void if removed
There might have been something wrong with the power supply to begin with,
it shouldn't be drawing more than a fraction of an amp before the system
is powered on.

hmmm... what do u suggest i do
 
K

kony

hmmm... what do u suggest i do


You refrained from opening it due to the sticker, so you need to see if
you can get a warranty replacement.. if you can't, the sticker is of
little use.
 
L

larrymoencurly

General Schvantzkoph said:
BTW isn't the 4 pin connector keyed? I would have thought
that it would be impossible to do what you did.

Never underestimate the ability of people to get around things like
that. ;)

I thought the same of PC133 memory, but my friend managed to not only
plug in a module backwards but also lock the latches. Mobo and memory
were OK (module got hot), but the PSU fried a transistor.
 
L

larrymoencurly

i find it strange that you say a normal cable doesn't have a fuse...
'cos i have those two PSUs and 3 cables... i can't remember which is
which... two of them are 5amp-fused, one is not... as mentioned above
about two fused ones, in addition, the unfused one gave me a nasty
spark when i plugged it in so i gave up on it...

The fuse in the cord is probably a good safety idea that isn't used in
all parts of the world, like North America.

Is it a good idea to keep using that PSU that went ka-boom? Because
if a filter capacitor was destroyed, the PSU could be putting out
pulsating DC on one of the rails, and only the filter capacitors on
the mobo are keeping the DC steady and allowing the PSU regulation to
work.
 
W

w_tom

Fuse is necessary because UK power board breaker is too
large for current capacity of power cords. US has no such
problem because US does not use ring circuits to power wall
receptacles and does not power those rings with 32 amp
breakers. All this safety stuff on both sides of the pond
have long been proven as necessary or unnecessary by decades
of experience.

One important circuit breaker is a 15 amp breaker on US
power strips. Breaker often missing on many grossly
overpriced protector type power strips and yet may be found on
$3 non-protector type strips. No breaker on that power strip
is, for example, why a kennel recently killed many dogs in the
resulting fire. Reason for this breaker should not be
confused with reason for fuse on UK power cords.
 
J

Jon Danniken

larrymoencurly said:
The fuse in the cord is probably a good safety idea that isn't used in
all parts of the world, like North America.

Fuses are for girly-men; real men just stick a paper clip in there. :)

Jon
 

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