If a just built PC goes bang on power-up...

F

Fred Finisterre

......what's the most likely thing I did wrong? I had a gunshot noise, a
flash, and smoke coming from (near) the PSU.

And which components are likely to be fried?

Cheers,

Fred.
 
C

Chris 159

Fred Finisterre said:
.....what's the most likely thing I did wrong? I had a gunshot noise, a
flash, and smoke coming from (near) the PSU.

And which components are likely to be fried?

Cheers,

Fred.


i'm guessing you got a part of the mobo shorted to the chassis in which case
you'll be lucky if its only the mobo and psu gone. cpu and ram aswell if
you're unlucky
 
B

BigH2K

Fred Finisterre said:
.....what's the most likely thing I did wrong? I had a gunshot noise, a
flash, and smoke coming from (near) the PSU.

And which components are likely to be fried?

Cheers,

Fred.

If you're lucky it's just the voltage selector switch on the PSU set
incorrectly, in which case your PSU is fried. If it was a decent quality PSU
then all your components should be fine, if it wasn't then look on the
bright side, it's still a nice case!
 
F

Fred Finisterre

If you're lucky it's just the voltage selector switch on the PSU set
incorrectly, in which case your PSU is fried. If it was a decent quality
PSU then all your components should be fine, if it wasn't then look on the
bright side, it's still a nice case!

It's an Antec Sonata case which comes with a 380W PSU. Where would I find
the voltage selector switch?

Cheers,

Fred.
 
F

Fred Finisterre

If you're lucky it's just the voltage selector switch on the PSU set
incorrectly, in which case your PSU is fried. If it was a decent
quality PSU then all your components should be fine, if it wasn't
then look on the bright side, it's still a nice case!

I think you're right. I never noticed the voltage selector switch. It was
set to 110V and I'm in the UK so should have had it set to 230V. Doh!
Bearing in mind the PSU looks like a fairly good one (True 380S), might I
have got away with just blowing the PSU?

Cheers,

Fred.
 
B

BigH2K

Fred Finisterre said:
It's an Antec Sonata case which comes with a 380W PSU. Where would I find
the voltage selector switch?

Cheers,

Fred.

Strangely, I have the same case and PSU so I can tell you that there isn't
one on this one. Good thing is if it was a faulty PSU then the rest of your
stuff is ok.

Can't really think of anything other than a PSU fault that could cause that
so you could really do with getting hold of another to test your system
with.
 
J

John Doe

Fred Finisterre said:
.....what's the most likely thing I did wrong? I had a gunshot
noise, a flash, and smoke coming from (near) the PSU.

Hopefully you unplugged your computer immediately following that
gunshot noise.

A capacitor can make a loud bang when high voltage is applied to its
leads. I did that accidentally once.

Another possibility is mini terrorists inside of your computer
[kidding].
And which components are likely to be fried?

Usually I swap components when I want to know what is bad.

Good luck.
 
B

BigH2K

Fred Finisterre said:
I think you're right. I never noticed the voltage selector switch. It was
set to 110V and I'm in the UK so should have had it set to 230V. Doh!
Bearing in mind the PSU looks like a fairly good one (True 380S), might I
have got away with just blowing the PSU?

Cheers,

Fred.

OK, so yours DOES have a voltage selector and mine doesn't.

Probably good news I would have thought, have swapped out many PSUs where
this has happened, even when the machines were on and switched over and
never had anything other than the PSU damaged.
 
W

w_tom

Voltage selector switch is adjacent to power cord
connection. A red slide switch that reads either 110 or 220.
BTW, universal power supplies can be used anywhere in the
world because they electronically select this switch - don't
depend on humans. Universal supplies are standard in laptops,
camcorders, and digital cameras. Many CRT video monitors also
contain universal supplies.

Unfortunately some would respond to your question
erroneously; without first learning basic facts. Any
acceptable computer power supply can be shorted and must not
suffer damage. Every power supply output wire can be shorted
together and still damage must not result. Intel specs even
say how large this shorting wire must be.

So why would another suggest a motherboard shorted to
chassis would cause PSU failure - and RAM & CPU damage?
Things damaged because the computer assembler buys his power
supplies on hype and price rather than using good technical
numbers. Too many computer assemblers only know that if A
mates to B, then it must be so. They don't need know anything
more to be an expert. They buy power supplies missing
essential functions which is why they suffer RAM and CPU
failure. Then they blame anything but themselves - the
technically naive computer assembler - as reason for failure.

If motherboard shorted to chassis causes RAM, CPU, or power
supply failure, then reason for that failure is directly
traceable to the human who bought components. As BigH2K says:
If it was a decent quality PSU then all your components
should be fine, ...

Why the pop? Probably a manufacturing defect. Exactly why
a computer assembler has a 3.5 digit multimeter to verify in
but seconds where the problem is located. Procedures
demonstrated previously in "Computer doesnt start at all" in
alt.comp.hardware on 10 Jan 2004 at
http://tinyurl.com/2t69q or
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://tinyurl.com/yvbw9 .
 
D

DaveW

Sounds like you blew, at minimum, one or more of the components in the power
supply. In addition, depending on the quality of build of the power supply
unit, you may also have fried the motherboard.
 
P

Papa

I've never seen a computer power supply that did not include the 110/220
selector switch. What brand and model number is the one you know about that
is missing that switch?
 
P

Papa

I looked up the Antec Sonata with 380 Watt power supply. The Antec
literature shows the 110/220 selector switch.
 
B

BigH2K

Papa said:
I looked up the Antec Sonata with 380 Watt power supply. The Antec
literature shows the 110/220 selector switch.

Well mine doesn't have one so there :p

As for you never having seen one that doesn't have a voltage selector well
you must have a very narrow field of experience in such matters. If you
really expect me to dismantle my PC so that I can provide you with a serial
number I suggest you go to bed, late night obviously make you unreasonable
:)

Only joking with you, it's very common to have PSUs without the selector,
Antec make a UK only model of this PSU and I suppose the switch was omitted
as a cost cutting exercise. You really only need the selector if you're
using it abroad and not many people actually transport their desktop
machined around with them.

Hang on a minute, if you send me a stamped addressed Jiffy Bag I'll send
mine to you to have a look ;)
 
P

Papa

Like many Americans, I get a little provincial at times. I shouldn't assume
that the whole world uses the exact same design variations as we do.
 
I

I.P.Freely

Fred Finisterre said:
.....what's the most likely thing I did wrong? I had a gunshot noise, a
flash, and smoke coming from (near) the PSU.

And which components are likely to be fried?


Depends.

If an Intel system, probably the PSU and possibly the motherboard but
doubtful.

If an AMD system, probably the PSU and also likely that the motherboard &
CPU has gone along with it, possibly also the memory.
 
J

John Doe

I.P.Freely said:
Depends.

If an Intel system, probably the PSU and possibly the motherboard but
doubtful.

If an AMD system, probably the PSU and also likely that the motherboard &
CPU has gone along with it, possibly also the memory.

Sounds like a troll (to me).
 
T

thoss

Fred Finisterre said:
I think you're right. I never noticed the voltage selector switch. It was
set to 110V and I'm in the UK so should have had it set to 230V. Doh!
Bearing in mind the PSU looks like a fairly good one (True 380S), might I
have got away with just blowing the PSU?
If you're very lucky, you might even have got away with just blowing the
fuse inside the PSU.
 
Z

Zotin Khuma

Fred Finisterre said:
It's an Antec Sonata case which comes with a 380W PSU. Where would I find
the voltage selector switch?

Cheers,

Fred.

The voltage selector, if it has one, will be at the rear of the PSU.
It's meant to switch between a 110/115V and a European 230/240-volt
line. If it's set at the lower voltage and you've connected it to your
240V line, what you heard was most probably the main filter capacitors
inside the PSU exploding - probably accompanied by a 'phffft' sound.
One poster here described it as a farting sound.

I've had a few cases like this with customers' computers and in all
cases there was no damage other than to the PSU itself.
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Top