Bloody computers

Right, before I go taking the other computer apart to try and find out
what's wrong with it, can any of the enlightened IT buffs here suggest
why a computer would go 'Phffft' and die (no smoke or smell of burning
though). It's not the fuse in the plug, that was the first obvious port
of call.

It was built about 12 months ago, as the processor was a faster one than
the previous the fan was also replaced as the original would not have
been sufficient to cool the processor.

It's been working fine until about 1 hour ago when it just decided to
die..and I won't get *any* peace until it's working again.

--
Lesley
ZXR400SP
"Not bad for a Scouser"
SBS#11[with oak-leaf cluster]
BOTAFOT#101A UKRMHRC#12
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if it has packed in completely then it is most likley the power supply. The
only way to tell is to open it. Send me a mail if you need help with how to
test it

 

PSU going titsup. If you got a faster process and a bigger fan it may
be that your old PSU wasn't powerful enough.

 

What he said: case=no lights, no fans inc PSU
case=fan, some lights, no boot then CPU = fubar / unseated


You might have a case of thermal creep where plugs can work their way
out of their sockets. If the PSU connector has come loose, it will
not sense the MOBO, and therefore not turn on (making it seem dead)

The same *can* happen to the CPU though it's bloody unlikely. This
can cause symptom set two.

Top off, check all the plugs. Try to restart.

It's always worth unplugging it for 10 mins or so. Sometimes helps.

PSUs these days are really cheap though. I just got a 450w job for
£15

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Ben says...

Ta Ben, the original system was AT, we also got an ATX case complete
with PSU when we got the other bits. Could be that though, and as luck
would have it I have a spare PSU sitting around that I can use, if that
doesn't work..

That would certainly be easier than farting around with the old AT
system replacing bits to get it up and running again.

--
Lesley
ZXR400SP
"Not bad for a Scouser"
SBS#11[with oak-leaf cluster]
BOTAFOT#101A UKRMHRC#12
BONY#54P BOB#18

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Was it a 'Phffft' or more like a 'Pop'? There was a *huuuuge* number of
dodgy capacitors[1] made in the last couple of years, and they have been
exploding for the last several months[2].

On any modern system the computer will shut itself down if the motherboard
detects the processor is overheating, so I doubt it's that.

Well the fact that it made a noise and then died would imply a larger
hardware problem (ie, not a chip blowing up). There is actually another fuse
inside the power supply, so it could have been that which blew.

You're not having electrical storms at the moment by any chance. I'd never
known of it happening to anyone before last year, but then two people I know
ended up with fried motherboards (and dead telephones) after a lightning
strike.

[1] Google for "capacitor stolen formula" for the whole hilarious story...
[2] Electrolyte boils and pops the cap off the end IIRC.

 

Sparkes says...

Thanks Steve. I'm not comfortable poking around with electrical stuff
though so I think I'll plump for the chicken way out and see if the PSU
we have spare gets it going.

--
Lesley
ZXR400SP
"Not bad for a Scouser"
SBS#11[with oak-leaf cluster]
BOTAFOT#101A UKRMHRC#12
BONY#54P BOB#18

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I have a spare ATX PSU sat here, but unless you're anywhere near Bristol
it's probably cheaper to get a new one than have me post it!

If you have to get a new one, go for a minimum of a 350W PSU.

 

Dan White says...

As luck would have it, the spare PSU got it working, no idea what the
fault is with the original one though, as the PSU fuse doesn't appear to
be foobarred.

Cheers all.

--
Lesley
ZXR400SP
"Not bad for a Scouser"
SBS#11[with oak-leaf cluster]
BOTAFOT#101A UKRMHRC#12
BONY#54P BOB#18

Un-cork me to reply

 

as Dan says, the phht was prolly a capacitor ejecting gas - have a look for
the telltale white powdery stuff scattered about the place. It's aluminium
oxidised during the explosion.

the extra current being drawn was probably enough to take out one of the
voltage regulators on the output side whereas the fuse is on the input side
of the PSU

 

Is this the same batch/source of capacitors that have been responsible
for Sky digiboxes slowly dying by creeping paralysis?

 

wessie says...

Hmm, I can't see any white powdery stuff, but there is a light brown
patch on the top of the PSU halfway between the capacitors and the fan,
don't suppose it would be unreasonable to assume that that is it?

Ta.

--
Lesley
ZXR400SP
"Not bad for a Scouser"
SBS#11[with oak-leaf cluster]
BOTAFOT#101A UKRMHRC#12
BONY#54P BOB#18

Un-cork me to reply

 

Very possibly.

To summarise from memory: Scientist working for component company "A"
defects to company "B" and nicks copies of the secret formula for their
capacitor electrolyte.

Unfortunately he neglects to take a copy of the formula for the stabilising
agent for the electrolyte. Company "B" churns out *hundreds of millions* of
said capacitors. Several months later, devices where the power is on
continuously began to fail, followed by less frequently used devices.

Good writeup in:
http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html#f1

 

Could well be. The electrolyte is like a brown cruddy substance, and the
dodgy capacitors were typically the larger ones involved in voltage
regulation/smoothing.

 

Dan White says...

Looks like that's the problem then. The replacement PSU is older than
the original, but looking at the write-up on the problem then it's
possible that this one could go the same way at some point.

Does it make any difference if the machine is on 24/7 or not?

--
Lesley
ZXR400SP
"Not bad for a Scouser"
SBS#11[with oak-leaf cluster]
BOTAFOT#101A UKRMHRC#12
BONY#54P BOB#18

Un-cork me to reply

 

DangerScouse wrote:

Brown stuff spread out around the fan?
I think you can guess what happened!


While we've got the 'pooter experts reading,
Anyone know of a "TV remote control" emulator that will
run on a laptop with infrared port?

 

I've got some software on my Ipaq called Nevo that does that.
However, they make a big deal about the fact that the Ipaqs IR made a
lot stronger in order to broadcast over a decent distance. A laptop
IR may not be as strong as it's only designed to be used at short
range.

 

Normally about 3 ft IME

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While recharging a flash gun in Spain many years ago[1] there was a
mains spike and the main capacitor went all over the hotel bedroom. You
would not believe hat a mess it made.

[1] When you charged the flash battery the gun went live.

 

*I* would

I built some perspex fronted speakers some years ago. One memorable
evening, they decided that the 110W RMS amps were too mcuh, and blew
the caps in the cross over. Oh boy

--
Catman MIB#14 SKoGA#6 TEAR#4 BOTAFOF#38 Apostle#21
Tyger, Tyger Burning Bright (Remove rust to reply)
Alfa 116 Giulietta 3.0l. Really, Sprint 1.7
Triumph Speed Triple: Black with extra black bits
www.cuore-sportivo.co.uk