Fried electricity smell - deadish pc

[ck26]

Hi. This morning I went to go onto my pc. It had obviously crashed during
the night since it was back at the windows log in screen. Funny. Nevermind,
I'm late for work. Came home from work switched it on, went to check on
dinner. Came back in and there was a really weird smell in the room - like
fried electricity. I didn't at first realise what it was, but then something
just told me to switch the pc off. Since then of course it hasn't worked. It
doesn't boot, there's no smell anymore, though. I've noticed the bottom fan
(I think its called the power supply box fan, or whatever the technical term
is) doesn't rotate anymore (or not noticeably). The hard drive light stays
on for quite a while, but I keep chickening out and switching the whole pc
off, because I don't want to cause any more damage.

Basically I think that perhaps its either the harddrive or the power supply.
Or possibly the ide cabling. I'm not sure and I need some advice. I put in
an old hardrive - no OS on it. It didn't boot obviously, but usually I would
expect to see an "invalid disk - replace and hit any key when ready" kind of
message, but no. The monitor doesn't even get woken up. The monitor is fine
though I'm 100% sure.

So, either the hardrive is fried or there's a power issue. How can I narrow
it down? I mentioned the ide cable because its slightly kinked, but not
seriously enough to warrant this kind of behaviour I don't believe. So -
shall I shell out on a new hard drive or a new power supply? Or at least
what can I test to make sure - I haven't got time tonight to try plugging
the hardrive into another machine. But I will possibly try tomorrow - unless
I'm on the wrong track completely - anyone?

Thanks for any advice. You people here are really great when it comes to
stuff like this - some of you have saved my butt loads of times and I owe
you a big and well respected thank you in advance.

 

[gorf]

Hi. This morning I went to go onto my pc. It had obviously crashed during
the night since it was back at the windows log in screen. Funny. Nevermind,
I'm late for work. Came home from work switched it on, went to check on
dinner. Came back in and there was a really weird smell in the room - like
fried electricity. I didn't at first realise what it was, but then something
just told me to switch the pc off. Since then of course it hasn't worked. It
doesn't boot, there's no smell anymore, though. I've noticed the bottom fan
(I think its called the power supply box fan, or whatever the technical term
is) doesn't rotate anymore (or not noticeably). The hard drive light stays
on for quite a while, but I keep chickening out and switching the whole pc
off, because I don't want to cause any more damage.

I had a powersupply burn out in our office, smelled of fried electronics
(some call it ozone, I don't really know). I could tell it was the PS
because there was scorching inside when I took it apart (hehe). The
components worked fine. In fact, the computer was still functioning when I
turned it off as a precaution.

You can disconnect the HD and see if it posts... it'll say something like
missing system disk. However, if probably won't post.

 

[kony]

Hi. This morning I went to go onto my pc. It had obviously crashed during
the night since it was back at the windows log in screen. Funny. Nevermind,
I'm late for work. Came home from work switched it on, went to check on
dinner. Came back in and there was a really weird smell in the room - like
fried electricity. I didn't at first realise what it was, but then something
just told me to switch the pc off. Since then of course it hasn't worked. It
doesn't boot, there's no smell anymore, though. I've noticed the bottom fan
(I think its called the power supply box fan, or whatever the technical term
is) doesn't rotate anymore (or not noticeably). The hard drive light stays
on for quite a while, but I keep chickening out and switching the whole pc
off, because I don't want to cause any more damage.

Basically I think that perhaps its either the harddrive or the power supply.
Or possibly the ide cabling. I'm not sure and I need some advice. I put in
an old hardrive - no OS on it. It didn't boot obviously, but usually I would
expect to see an "invalid disk - replace and hit any key when ready" kind of
message, but no. The monitor doesn't even get woken up. The monitor is fine
though I'm 100% sure.

So, either the hardrive is fried or there's a power issue. How can I narrow
it down? I mentioned the ide cable because its slightly kinked, but not
seriously enough to warrant this kind of behaviour I don't believe. So -
shall I shell out on a new hard drive or a new power supply? Or at least
what can I test to make sure - I haven't got time tonight to try plugging
the hardrive into another machine. But I will possibly try tomorrow - unless
I'm on the wrong track completely - anyone?

Thanks for any advice. You people here are really great when it comes to
stuff like this - some of you have saved my butt loads of times and I owe
you a big and well respected thank you in advance.

Open the system, inspect the motherboard (particularly the capacitors)
and sniff the power supply.

If you have the opportunity, check the power supply voltages with a
voltage meter. You might also disconnect the power supply from AC,
remove it, and after a few minutes have elapsed open it and inspect it
inside... usually there's visable sign of such failure.

I doubt it has anything to do with the hard drive. The light on the
case may simply be on because the system stopped in that phase of
power-on. As another poster suggested you might just disconnect the
hard drive, and could also disconnect everything else too... only the
CPU, CPU fan, one memory module, and video card are needed to POST,
get something on the monitor... even keyboard/mouse/etc can be
disconnected.

When you check the power supply see if the rear fan spins freely (a
simple touch with a finger to see how easily it turns while off, is
enough).


Dave

 

[ck26]

Open the system, inspect the motherboard (particularly the capacitors)

and sniff the power supply.

Right, nothing dodgy smelling now, but when I took the case off and sniffed
around yesterday, something smelt and I think it was the power supply,
although I'm only 60-70% sure.

If you have the opportunity, check the power supply voltages with a
voltage meter. You might also disconnect the power supply from AC,
remove it, and after a few minutes have elapsed open it and inspect it
inside... usually there's visable sign of such failure.

OK, I haven't got a voltage meter, but I've taken apart the PSU and there's
nothing obvious wrong with it - it was a bit dusty though. I thought the
macdonalds cheese all over the components inside the PSU was a tell-tale
sign, until I realised that it was glue, and it probably should be there.

I doubt it has anything to do with the hard drive. The light on the
case may simply be on because the system stopped in that phase of
power-on. As another poster suggested you might just disconnect the
hard drive, and could also disconnect everything else too... only the
CPU, CPU fan, one memory module, and video card are needed to POST,
get something on the monitor... even keyboard/mouse/etc can be
disconnected.

It doesn't post - I've tried the HD in another machine and at least it
registers - it did have a non-bootable win2k message - but I think in my
hurry to see if it worked I had merely forgotten to change the master /
slave pins. So I guess the HD is fine for now.

When you check the power supply see if the rear fan spins freely (a
simple touch with a finger to see how easily it turns while off, is
enough).

This is what is puzzling me a bit - the fan spins about an eighth of a turn
when you try to spin it. The other fans in the case seem to spin very
freely - like a whole turn. However, I can't seem to see what could be
preventing it from spinnning easily - the PSU is now completely outside of
the case and there's no wires in its way - no dust, no debris, etc, it just
doesn't spin, there doesn't even seem to be an obvious place to lubricate it
into spinning more freely either.

Conclusion: I'm not sure now what could be wrong? Is it the PSU? There's no
burn marks anywhere inside the machine or the PSU. The only conclusions that
I have drawn are that I'm still not sure what to do. I might resort to
pulling the PSU from an older machine and trying that. Any other ideas
before I try that?

Thanks for the suggestions.

 

[V W Wall]

This is what is puzzling me a bit - the fan spins about an eighth of a turn
when you try to spin it. The other fans in the case seem to spin very
freely - like a whole turn. However, I can't seem to see what could be
preventing it from spinnning easily - the PSU is now completely outside of
the case and there's no wires in its way - no dust, no debris, etc, it just
doesn't spin, there doesn't even seem to be an obvious place to lubricate it
into spinning more freely either.

It's probably a sleeve bearing fan motor, and the bearings have gone dry. You
can peel off the metalic sticker on the hub, remove a rubber plug if present,
and apply a drop of heavy oil. This may free up the bearing. I've had
some repaired this way last for years, and others fail in hours. New fan/motors
are inexpensive and are the best way to go. Most don't have connectors, so need
the wires to be soldered, but even stripping and twisting the wires together
will
work. Just make sure they're insulated with tape and don't intefere with the
fan's rotation. DON'T use WD-40, it's not a lubricant.

Conclusion: I'm not sure now what could be wrong? Is it the PSU? There's no
burn marks anywhere inside the machine or the PSU. The only conclusions that
I have drawn are that I'm still not sure what to do. I might resort to
pulling the PSU from an older machine and trying that. Any other ideas
before I try that?

A failed PS fan may not be the entire problem, but it needs to be fixed. It
might have caused the entire PS to fail.

Virg Wall

 

[ck26]

It's probably a sleeve bearing fan motor, and the bearings have gone dry.
You

can peel off the metalic sticker on the hub, remove a rubber plug if present,
and apply a drop of heavy oil. This may free up the bearing. I've had
some repaired this way last for years, and others fail in hours. New fan/motors
are inexpensive and are the best way to go. Most don't have connectors, so need
the wires to be soldered, but even stripping and twisting the wires together
will
work. Just make sure they're insulated with tape and don't intefere with the
fan's rotation. DON'T use WD-40, it's not a lubricant.

Thanks for that - I did as you suggested and added some oil. It work great
after that. The only problem now is that the PSU fan works, the power supply
is powering everything I can easily tell - the other fans in the case, the
motherboard, the cd drives, the floppy. But I'm not getting any post at all.
I took the lid off and noticed a green LED light underneath the IDE cables
was on - is that normal?

A failed PS fan may not be the entire problem, but it needs to be fixed. It
might have caused the entire PS to fail.

I guess you are right there - trouble is, is there a definitive way to no
that the PSU has partially failed already - or is there some other
explanation for this problem? I really don't want to buy a new PSU if it
really isn't the problem...

 

[V W Wall]

Thanks for that - I did as you suggested and added some oil. It work great
after that. The only problem now is that the PSU fan works, the power supply
is powering everything I can easily tell - the other fans in the case, the
motherboard, the cd drives, the floppy. But I'm not getting any post at all.
I took the lid off and noticed a green LED light underneath the IDE cables
was on - is that normal?

Some MBs have a light to indicate the presence of +5V SB, when the PS is plugged
in to the line but not turned on by the front panel power switch. This is
normal.

I guess you are right there - trouble is, is there a definitive way to no
that the PSU has partially failed already - or is there some other
explanation for this problem? I really don't want to buy a new PSU if it
really isn't the problem...

You know the +12V from the power supply is available. It's used for the fans
and the drive motors. Without a voltmeter, trying a PS from a known working
system may be the easiest. DVMs are available for about $20 and up. If you
do much work on PCs, it's well worth buying one. You could use a 6V auto
tail lamp to check the +5V when the supply is on. 5V will appear between
the red and black wires on any four pin power connector. Getting the lamp
wired to the connector may be a problem if you can't solder wires to it.

You can try to get the system to post by removing everything but one stick of
memory, the video display card, and a floppy drive with a boot floppy in it.
The BIOS will fail to start from the HD, but should use the floppy to boot
into DOS. You can then replace the HD, and see if the BIOS finds it. If
you don't have a boot disk, get the correct one from www.bootdisk.com.

Virg Wall

 

[Trent©]

Hi. This morning I went to go onto my pc. It had obviously crashed during
the night since it was back at the windows log in screen.

What operating system?

Funny. Nevermind,
I'm late for work. Came home from work switched it on, went to check on
dinner. Came back in and there was a really weird smell in the room - like
fried electricity. I didn't at first realise what it was, but then something
just told me to switch the pc off.

So...the machine had booted okay?...and you logged off at this point
and turned it off?

Since then of course it hasn't worked. It
doesn't boot, there's no smell anymore, though. I've noticed the bottom fan
(I think its called the power supply box fan, or whatever the technical term
is) doesn't rotate anymore (or not noticeably). The hard drive light stays
on for quite a while, but I keep chickening out and switching the whole pc
off, because I don't want to cause any more damage.

Yer gonna hafta try it SOMETIME! lol

Basically I think that perhaps its either the harddrive or the power supply.
Or possibly the ide cabling. I'm not sure and I need some advice. I put in
an old hardrive - no OS on it. It didn't boot obviously, but usually I would
expect to see an "invalid disk - replace and hit any key when ready" kind of
message, but no. The monitor doesn't even get woken up. The monitor is fine
though I'm 100% sure.

It almost sounds like the CPU got fried.

So, either the hardrive is fried or there's a power issue. How can I narrow
it down?

Disconnect everything except the CPU/fan...video...1 stick of
RAM...keyboard. Boot and see if you can get to the CMOS screen.

I mentioned the ide cable because its slightly kinked, but not
seriously enough to warrant this kind of behaviour I don't believe. So -
shall I shell out on a new hard drive or a new power supply?

You don't need a hard drive installed to do some of the basic tests
you can do...including the above.

See if you can boot into the CMOS screen. And pay attention to see if
your CPU fan is working.

Good luck...let us know.


Have a nice week...

Trent

Fighting for peace is like screwing for virginity!

 

[w_tom]

You are simply guessing. Stuck power supply fan may have
caused power supply failure. But you are still guessing.
There is no faster and more informative way to verify PSU
integrity than the 3.5 digit multimeter. Don't screw around.
Buy a meter that is so inexpensive as to be sold in Lowes,
Radio Shack, Home Depot, Sears, and so many other places.
Measure those voltages per chart at:
http://www.hardwaresite.net/faqpowersupply.html

You want the most definitive way? As kony said, "check the
power supply voltages with a voltage meter." EVen if fan spins
and green LED shines, you still don't know if voltages are
OK. Once the PSU is verified with a multimeter, only then is
one component known good. Use that good component to 'step
stone' integrity checks of other components. Verify that
power supply first so that other components can next be
verified. Get the meter so that time is not wasted.

 

[ck26]

What operating system?

Sorry - win2k

So...the machine had booted okay?...and you logged off at this point
and turned it off?

It had obviously booted OK since it was at the log-in screen with no errors.
However - the smell and this weird "electricity in the air" kind of feeling
just told me to switch it off immediately. So I didn't do a clean shutdown -
I just switched it off by holding the power button down for 3 seconds.

It almost sounds like the CPU got fried.

Really?! Oh no! What makes you think that? How could I verify that easily?

Disconnect everything except the CPU/fan...video...1 stick of
RAM...keyboard. Boot and see if you can get to the CMOS screen.

Nothing. The monitor doesn't even wake up - it just flashes like it does
when it has power, but when the machine is switched off.

See if you can boot into the CMOS screen. And pay attention to see if
your CPU fan is working.

Nope. But I can physically see the CPU fan working.

Thanks for the help.

 

[Trent©]

Sorry - win2k


It had obviously booted OK since it was at the log-in screen with no errors.
However - the smell and this weird "electricity in the air" kind of feeling
just told me to switch it off immediately. So I didn't do a clean shutdown -
I just switched it off by holding the power button down for 3 seconds.


Really?! Oh no! What makes you think that? How could I verify that easily?


Nothing. The monitor doesn't even wake up - it just flashes like it does
when it has power, but when the machine is switched off.


Nope. But I can physically see the CPU fan working.

Thanks for the help.

Then my guess would be the mainboard or the CPU. But it could be any
of the major components...primarily because of the smell that you said
you noticed.

You've simply gotta swap parts to find the real culprit.

I'd take the others good advice, though, and get a digital VOM to do
some checking of the power supply. You can buy a sufficient meter for
under $2 at places like Harbor Freight.



Have a nice week...

Trent

Fighting for peace is like screwing for virginity!