|
|
Uh oh.
I'm on the laptop now, because the desktop won't turn on. It was working
fine, then a piece of ice from our winter weather jiggled the electrical
lines. The house-lights flickered and the computer quit. All the
peripherals and all the house lights are working fine. I cannot get the
desktop computer to turn on. No indicator lights, either. Yes, everything
was plugged into a surge protector.
Is there some kind of a power connector inside the computer itself that may
have gone out? Or have I lost my motherboard? How do I figure out what's
broken and how to fix it?
Thanks.
--
<*(((><
|
|
open the case, turn the pc on, does any fan start turning? if not it's the
power supply, if it does then you fried something on the MB.
When I say any fan I also mean the fan on the powersupply.
"<*(((><{" wrote:
[Quoted Text] > Uh oh.
> I'm on the laptop now, because the desktop won't turn on. It was working
> fine, then a piece of ice from our winter weather jiggled the electrical
> lines. The house-lights flickered and the computer quit. All the
> peripherals and all the house lights are working fine. I cannot get the
> desktop computer to turn on. No indicator lights, either. Yes, everything
> was plugged into a surge protector.
>
> Is there some kind of a power connector inside the computer itself that may
> have gone out? Or have I lost my motherboard? How do I figure out what's
> broken and how to fix it?
>
> Thanks.
>
> --
>
> <*(((><
>
>
>
>
>
|
|
No. The fan does not start running.
So I need to order a new power supply?
Are there two fans? One on the power supply and another somewhere else?
What should I order?
--
<*(((><
"sgopus" <sgopus[ at ]discussions.microsoft.com> wrote in message
news:80AB427C-6D6E-40E0-A307-CA5DDFE0D8E3[ at ]microsoft.com...
[Quoted Text] > open the case, turn the pc on, does any fan start turning? if not it's
> the
> power supply, if it does then you fried something on the MB.
> When I say any fan I also mean the fan on the powersupply.
>
> "<*(((><{" wrote:
>
>> Uh oh.
>> I'm on the laptop now, because the desktop won't turn on. It was working
>> fine, then a piece of ice from our winter weather jiggled the electrical
>> lines. The house-lights flickered and the computer quit. All the
>> peripherals and all the house lights are working fine. I cannot get the
>> desktop computer to turn on. No indicator lights, either. Yes,
>> everything
>> was plugged into a surge protector.
>>
>> Is there some kind of a power connector inside the computer itself that
>> may
>> have gone out? Or have I lost my motherboard? How do I figure out
>> what's
>> broken and how to fix it?
>>
>> Thanks.
>>
>> --
>>
>> <*(((><
>>
>>
>>
>>
>>
|
|
There is a Power Supply fan, CPU Fan, PC Case Fan
and most likely a fan on the Video card.
JS
http://www.pagestart.com
"<*(((><{" <Fishy[ at ]ocean.net> wrote in message
news:uP9g5b9YJHA.1268[ at ]TK2MSFTNGP04.phx.gbl...
[Quoted Text] > No. The fan does not start running.
> So I need to order a new power supply?
> Are there two fans? One on the power supply and another somewhere else?
> What should I order?
>
>
>
> --
>
> <*(((><
>
>
>
> "sgopus" <sgopus[ at ]discussions.microsoft.com> wrote in message
> news:80AB427C-6D6E-40E0-A307-CA5DDFE0D8E3[ at ]microsoft.com...
>> open the case, turn the pc on, does any fan start turning? if not it's
>> the
>> power supply, if it does then you fried something on the MB.
>> When I say any fan I also mean the fan on the powersupply.
>>
>> "<*(((><{" wrote:
>>
>>> Uh oh.
>>> I'm on the laptop now, because the desktop won't turn on. It was
>>> working
>>> fine, then a piece of ice from our winter weather jiggled the electrical
>>> lines. The house-lights flickered and the computer quit. All the
>>> peripherals and all the house lights are working fine. I cannot get the
>>> desktop computer to turn on. No indicator lights, either. Yes,
>>> everything
>>> was plugged into a surge protector.
>>>
>>> Is there some kind of a power connector inside the computer itself that
>>> may
>>> have gone out? Or have I lost my motherboard? How do I figure out
>>> what's
>>> broken and how to fix it?
>>>
>>> Thanks.
>>>
>>> --
>>>
>>> <*(((><
>>>
>>>
>>>
>>>
>>>
>
>
|
|
Lots of fans. Keep in mind that this desktop ATX case was put together in
2001. So however many fans would have been used then.
I've been looking at power supplies at NewEgg -- they range from $11 to $22.
Some have two fans, some one. Some fans are 80 mm and some are 120. Some
advertise ball bearings, others say "low noise, low ripple, super quiet"
etc. Most says 20+4 pin, and a couple say 24 pin. A few are "top mount."
This is an ordinary desktop--no gaming or video. Does it matter much what
kind of a power supply I buy?
<*(((><
"JS" <[ at ]> wrote in message news:uHj5A59YJHA.1184[ at ]TK2MSFTNGP05.phx.gbl...
[Quoted Text] > There is a Power Supply fan, CPU Fan, PC Case Fan > and most likely a fan on the Video card. > > JS > http://www.pagestart.com> > > "<*(((><{" <Fishy[ at ]ocean.net> wrote in message > news:uP9g5b9YJHA.1268[ at ]TK2MSFTNGP04.phx.gbl... >> No. The fan does not start running. >> So I need to order a new power supply? >> Are there two fans? One on the power supply and another somewhere else? >> What should I order? >> >> >> >> -- >> >> <*(((>< >> >> >> >> "sgopus" <sgopus[ at ]discussions.microsoft.com> wrote in message >> news:80AB427C-6D6E-40E0-A307-CA5DDFE0D8E3[ at ]microsoft.com... >>> open the case, turn the pc on, does any fan start turning? if not it's >>> the >>> power supply, if it does then you fried something on the MB. >>> When I say any fan I also mean the fan on the powersupply. >>> >>> "<*(((><{" wrote: >>> >>>> Uh oh. >>>> I'm on the laptop now, because the desktop won't turn on. It was >>>> working >>>> fine, then a piece of ice from our winter weather jiggled the >>>> electrical >>>> lines. The house-lights flickered and the computer quit. All the >>>> peripherals and all the house lights are working fine. I cannot get >>>> the >>>> desktop computer to turn on. No indicator lights, either. Yes, >>>> everything >>>> was plugged into a surge protector. >>>> >>>> Is there some kind of a power connector inside the computer itself that >>>> may >>>> have gone out? Or have I lost my motherboard? How do I figure out >>>> what's >>>> broken and how to fix it? >>>> >>>> Thanks. >>>> >>>> -- >>>> >>>> <*(((>< >>>> >>>> >>>> >>>> >>>> >> >> > >
|
|
[Quoted Text] >>>> "<*(((><{" wrote:
>>>>> Uh oh.
>>>>> I'm on the laptop now, because the desktop won't turn on. It was
>>>>> working fine, then a piece of ice from our winter weather jiggled the
>>>>> electrical lines. The house-lights flickered and the computer quit.
>>>>> All the
>>>>> peripherals and all the house lights are working fine. I cannot get
>>>>> the desktop computer to turn on. No indicator lights, either. Yes,
>>>>> everything was plugged into a surge protector.
>>>>>
>>>>> Is there some kind of a power connector inside the computer itself
>>>>> that may have gone out? Or have I lost my motherboard? How do I
>>>>> figure out what's broken and how to fix it?
>>>>>
>>>>> Thanks.
>>>>> --
>>>>> <*(((><
>>> "sgopus" <sgopus[ at ]discussions.microsoft.com> wrote in message
>>> news:80AB427C-6D6E-40E0-A307-CA5DDFE0D8E3[ at ]microsoft.com...
>>>> open the case, turn the pc on, does any fan start turning? if not it's
>>>> the
>>>> power supply, if it does then you fried something on the MB.
>>>> When I say any fan I also mean the fan on the powersupply.
"<*(((><{" <Fishy[ at ]ocean.net> wrote in message
news:OBLHaO%23YJHA.728[ at ]TK2MSFTNGP02.phx.gbl...
> Lots of fans. Keep in mind that this desktop ATX case was put together in
> 2001. So however many fans would have been used then.
>
> I've been looking at power supplies at NewEgg -- they range from $11 to
> $22. Some have two fans, some one. Some fans are 80 mm and some are 120.
> Some advertise ball bearings, others say "low noise, low ripple, super
> quiet" etc. Most says 20+4 pin, and a couple say 24 pin. A few are "top
> mount."
>
> This is an ordinary desktop--no gaming or video. Does it matter much what
> kind of a power supply I buy?
>
> <*(((><
<*(((etc. etc...
Well, before you start going out buying a power supply (PSU), let's discuss
your situation for a moment, OK?
While it *could* be a defective PSU that's the culprit re your problem,
there's a strong possibility that it's not. Power surges ordinarily do not
take out one's PSU, although it *is* a possibility.
As a general proposition the more likely "culprit" is a blown motherboard.
That component usually bears the brunt of a power surge.
Obviously as an end-user you have a problem diagnosing the cause of your
problem (let alone a decision as to how to remedy the situation given that
you're dealing with a very old PC measured in "computer time" of course).
The most accurate way for you to determine if the problem results from a
defective PSU is to substitute a known good one for the present one.
Obviously that's not available to you since I take it you would have to
purchase a new PSU to do so.
Another diagnostic tool is a power tester but I guess you don't have that
device available either. They cost about $15 to $20 (incl. shipping) from
the online vendors, but not much cheaper than the cost of the PSU's you
mentioned in your last post. Those cheapo PSUs that you quoted can be quite
unreliable but on the other hand we've encountered some that surprisingly
worked reliably for many years. But it's a crapshoot at best and I really
can't give you any recommendation since those inexpensive PSUs seem to be
continuously manufactured by different sources. In any event I don't imagine
you would like to spend a fair amount of money for a higher-end PSU given
the age of your PC (unless, of course, you're planning to build a more
"modern" machine in the near future).
Anyway, I have my doubts as to whether the PSU is the cause of your problem
although *again* it's quite possible. If you do conclude it's a defective
PSU and you decide to purchase a new PSU, keep in mind that your PC has a
20-pin power connector - not the newer 24-pin connectors. (I'm assuming your
motherboard dates back to 2001, right?). Most PSUs will be compatible with
either type connector since an adapter device of one sort or another is
generally available with the PSU. But keep this in mind.
I'm still leaning toward a blown motherboard as the cause of your problem.
Have you been able to visually inspect the motherboard? Any indications of
blackened components there? If so, that would be just about definitive it's
the motherboard. Absent that, again the only way for you to determine if it
is the motherboard is (once again) via the substitution route. Needless to
say that becomes difficult, if not impossible, for most users.
It could even be your processor, what is generally known as the CPU.
Doubtful, but possible.
Or even a combination of defective components.
While you could have a computer shop look it over, I really think the costs
involved there (diagnosis & possible repair) just would be too much to bear
given this is a 8-year-old machine.
I realize I probably haven't been too helpful to you but this is a
difficult situation given the age of your machine and the limited ways you
can diagnose the problem let alone correct it. Just think hard & long before
you go out purchasing this or that component. I see brand-new off-the-shelf
desktop PCs selling in the mass-merchandise stores in the $300 to $400
range. Needless to say their performance will be substantially better than
your present machine (even if you have to swallow Vista). And since you
already have a monitor & printer (right?), it's something to think about,
no?
Anna
|
|
"<*(((><{" <Fishy[ at ]ocean.net> wrote in message
news:uGM5xT9YJHA.4456[ at ]TK2MSFTNGP04.phx.gbl...
[Quoted Text] > Uh oh.
> I'm on the laptop now, because the desktop won't turn on. It was working
> fine, then a piece of ice from our winter weather jiggled the electrical
> lines. The house-lights flickered and the computer quit. All the
> peripherals and all the house lights are working fine. I cannot get the
> desktop computer to turn on. No indicator lights, either. Yes,
> everything was plugged into a surge protector.
>
> Is there some kind of a power connector inside the computer itself that
> may have gone out? Or have I lost my motherboard? How do I figure out
> what's broken and how to fix it?
>
> Thanks.
>
> --
>
> <*(((><
>
>
>
>
Look at the obvious first. Does the computer work when plugged into the
working wall outlet without the surge protector? Surge protectors are
designed to stop surges into a device. Some give their lives in order to
protect the ones they "love."
|
|
<*(((><{ wrote:
[Quoted Text] > Lots of fans. Keep in mind that this desktop ATX case was put together in
> 2001. So however many fans would have been used then.
>
> I've been looking at power supplies at NewEgg -- they range from $11 to $22.
> Some have two fans, some one. Some fans are 80 mm and some are 120. Some
> advertise ball bearings, others say "low noise, low ripple, super quiet"
> etc. Most says 20+4 pin, and a couple say 24 pin. A few are "top mount."
>
> This is an ordinary desktop--no gaming or video. Does it matter much what
> kind of a power supply I buy?
>
> <*(((><
The side of the power supply will have a label on it. You want
a supply that matches or exceeds the characteristics. Speaking
in very general terms (without going into what each number means,
and they *are* important), you'd want a 350W or greater supply,
to replace the broken 350W supply.
Buying an $11 to $22 supply is a mistake. Those are "bargoon"
supplies. Read the reviewer comments on Newegg, to see how
many were dead on arrival, how many blew when used, and how long
they last. I remember one bright guy, who bought four of the
same cheap supply sequentially (first one blows, buys a second,
that blows, buys a third...) and never clued into the fact that
he ended up paying a fortune for his supply.
My last replacement supply cost me about $60, runs cool and
behaves well. It is made by Enermax. Even they aren't perfect,
but chances are the supply I got, will last longer than the
$11 one.
To test a supply, you can try this.
1) Disconnect the supply from the computer. We don't know
what defect it has. You didn't say what brand of computer it
is, and you could have an Emachine with a 250W Bestec supply in it.
Those tend to blow, and take out the motherboard when they go.
Many other supplies have defensive circuitry of one sort or
another, reducing to some extent, the odds of that happening.
It is still possible, for the world's best designed supply,
to be damaged by a lightning strike, so there are limits to
what they can defend against.
2) Ideally, you want to place some load on the supply. Some older
supplies, might need a small load to help them maintain regulation.
The ATX supply is not a push pull design - it likes to source
current, but cannot sink current if the voltage rises too high.
I personally haven't had any trouble here with that, and the
supplies I've tried generally seemed to work OK without a load
on them. (Some supplies cheat, and have a dynamic load circuit in
them, that switches on when no external load is present.) I also
have a load box, which draws 100W total or so, distributed over
all the output rails (each rail gets a load resistor, and the
-12V rail has a 50 ohm load and so on). When I buy a new supply,
I leave it simmering with the load box on it for two hours, just
to make sure it isn't a dud. I check the voltages delivered
with a multimeter.
3) So ignoring (2) in the interest of time, you connect PS_ON# to
COM. PS_ON# is usually a green wire, while COM, also known as
ground, is a black wire. When PS_ON# is connected to COM, that
causes the power supply to soft start. The cooling fan should
then start to spin on the supply. See the wiring table with colors
and pin numbers, in these docs. First doc is for 20 pin supplies,
second is for 24 pin supplies.
http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf (page 30)
http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf (page 37)
4) If you had a multimeter, you could measure the voltages on
the main power harness, while the PSU is running with the PS_ON#
pin connected to one of the adjacent COM pins.
A similar technique can be used, to turn on a computer which fails
to assert PS_ON#. The motherboard normally grounds PS_ON# when it
wants the PSU to run. You can safely connect PS_ON# to COM,
with the main connector plugged into the motherboard (shorting the
motherboard driver won't hurt it, because it is supposed to be
open collector). But what that also does, is override motherboard
safety features. For example, if the motherboard detects a problem
(like CPU overheat), it needs to be able to turn off the PS_ON# signal.
If you still have your shorting wire present, the power stays on and
the CPU eventually gets cooked. So while the "paper clip trick" can be
used to solve a situation where the PS_ON# driver on the motherboard
is broken, there can be resulting collateral damage if something
else goes wrong.
In terms of 20 pin versus 20+4 pin supplies, the 20+4 pin main
connector has a hinged section which can be removed. For example,
oh my new Enermax, I have the +4 pin section disconnected from
the main connector, since the motherboard is a 20 pinner. There
are a very few 24 pin power supplies, where they neglected to
hinge the four pins on one end, and for those, you can still
plug the connector in, as long as no tall components are in the
way. Pin 1 of the 24 pin, goes to Pin 1 of the 20 pin motherboard
connector. The four "left over pins" would hang over one
end. If they're the hinged type, they can be removed.
The extra four pins don't introduce any new voltages, and are
only present to carry extra current if needed. The most typical
situation where the extra pins are needed, is on computers which
have two PCI Express video cards installed. For most other situations,
the extra pins are not needed.
You can see a picture of the "paper clip trick" here. PSU plugged
into the wall, and switched on at the back, then the paper clip
stays in position for as long as you want it to stay on. It looks
like they connected pin 14 (PS_ON#) to pin 16 (COM). There are four
black COM wires in the vicinity. The green wire is on the side
with the plastic latch.
http://www.chirio.com/IMAGES/atx_012_ps_on.jpg
HTH,
Paul
|
|
On Dec 21, 8:28 pm, "<*\(\(\(><{" <Fi...[ at ]ocean.net> wrote:
[Quoted Text] > I'm on the laptop now, because the desktop won't turn on. It was working
> fine, then a piece of ice from our winter weather jiggled the electrical
> lines. The house-lights flickered and thecomputerquit. All the
> peripherals and all the house lights are working fine.
Posts from Anna and Paul are your useful replies. Others said, it
could be this or could be that or could be the other thing ... so
replace the power supply. That is how the naive fix things.
In but 30 seconds with a multimeter (a tool so complex as to be sold
in Kmart and in stores where hammers are sold), your question is
quickly answered OR numbers result in useful replies from the few who
actually know this stuff.
Anna is right. Your failure could be most any part. However, a
power supply tester, that costs as much as the multimeter, 1) has no
other purpose, and 2) will not provide numbers so that the better
informed can provide answers. Better is to spend about same for a
multimeter.
Paul is also correct about power supply prices. Let's see. How
many other electronics devices also failed? Furnace, dishwasher,
microwave oven, clock radios? A cheap power supply (missing essential
functions) could fail or could contribute to motherboard failure.
All those other electronics devices did not fail - had a sufficient
power supply? Good reasons why responsible manufacturers use
supplies that costs $60 full retail - not $20 power supplies. Those
$20 supplies are marketed to computer assemblers who don't have basic
electrical knowledge.
Using the meter. Set multimeter to 20 VDC range. Connect black
wire to metal chassis. Measure (with red lead) the green, gray and
purple wires (from power supply to motherboard) both before and when
power switch is pressed. Record those numbers and report them here to
understand what you have AND learn how simple the suspect is
identified. Also measure voltages on any one of orange, yellow, and
red wires after power switch is pressed. Those last three wires will
probably report zero. But to get a useful reply, that information is
also provided. Don't short your help of facts and numbers.
First and foremost, you should see 4.87 volts or higher on the
purple wire. If not, disconnect the AC power plug, disconnect the
power supply connector from motherboard, restore AC power plug, and
measure that purple wire again. If voltage is still too low, then
power supply is defective. One example of finding a problem before
fixing anything. Get the meter - that is even sold in Wal-mart and
Lowes for about the same price as a power supply tester.
|
|
On Sun, 21 Dec 2008 17:28:53 -0800, "<*\(\(\(><{" <Fishy[ at ]ocean.net> wrote:
[Quoted Text] >Uh oh.
>I'm on the laptop now, because the desktop won't turn on. It was working
>fine, then a piece of ice from our winter weather jiggled the electrical
>lines. The house-lights flickered and the computer quit. All the
>peripherals and all the house lights are working fine. I cannot get the
>desktop computer to turn on. No indicator lights, either. Yes, everything
>was plugged into a surge protector.
>
>Is there some kind of a power connector inside the computer itself that may
>have gone out? Or have I lost my motherboard? How do I figure out what's
>broken and how to fix it?
>
>Thanks.
On the back of the power supply, where the A/C cord plugs in, is there a switch
marked with a I and a O. If so, press the O side to shut it off and leave it that
way for about a minute. Then, press the I side to turn it back on and see if you
have power.
Everyone: ever heard of a 'crowbar' circuit?
NRJ
|
|
Just so other people that read this post aren't sent astray, this is
entirely incorrect. If the PC has no power at all it does not mean it's the
power supply with 100% certainty, a fried motherboard can also do this
(along with RAM, PCI cards, etc.). Same goes for your second "suggestions",
just because the fans spin up does NOT mean the power supply is good, nor
does it mean the motherboard is bad.
--
----
Crosspost, do not multipost http://www.blakjak.demon.co.uk/mul_crss.htm
How to ask a question http://support.microsoft.com/kb/555375
Help Us Help You http://dts-l.net/goodpost.htm
"sgopus" <sgopus[ at ]discussions.microsoft.com> wrote in message
news:80AB427C-6D6E-40E0-A307-CA5DDFE0D8E3[ at ]microsoft.com...
[Quoted Text] > open the case, turn the pc on, does any fan start turning? if not it's
> the
> power supply, if it does then you fried something on the MB.
> When I say any fan I also mean the fan on the powersupply.
|
|
Yep, but I shot the crow because he
was making too much noise ;-)
As for the real problem as Anna and others
have indicated it could be any number of one
or more things. When my server power supply died
and took the motherboard and CPU with it.
--
JS
http://www.pagestart.com
<I_cannot_say[ at ]nowhere.net> wrote in message
news:ke7vk4dj3n00p4m4rg00tk1tmbb4jleaqe[ at ]4ax.com...
[Quoted Text] > On Sun, 21 Dec 2008 17:28:53 -0800, "<*\(\(\(><{" <Fishy[ at ]ocean.net> wrote:
>
>>Uh oh.
>>I'm on the laptop now, because the desktop won't turn on. It was working
>>fine, then a piece of ice from our winter weather jiggled the electrical
>>lines. The house-lights flickered and the computer quit. All the
>>peripherals and all the house lights are working fine. I cannot get the
>>desktop computer to turn on. No indicator lights, either. Yes,
>>everything
>>was plugged into a surge protector.
>>
>>Is there some kind of a power connector inside the computer itself that
>>may
>>have gone out? Or have I lost my motherboard? How do I figure out what's
>>broken and how to fix it?
>>
>>Thanks.
>
> On the back of the power supply, where the A/C cord plugs in, is there a
> switch
> marked with a I and a O. If so, press the O side to shut it off and leave
> it that
> way for about a minute. Then, press the I side to turn it back on and see
> if you
> have power.
>
> Everyone: ever heard of a 'crowbar' circuit?
>
> NRJ
|
|
To everybody who responded:
Lots of helpful information for me!
The snow is falling harder and I'm stuck in the house and Christmas is
coming and .... I won't have a chance to work on my desktop NO POWER problem
for at least a week.
I'll keep the responses and reply back next week.
Merry Christmas!
--
<*(((><
"<*(((><{" <Fishy[ at ]ocean.net> wrote in message
news:uGM5xT9YJHA.4456[ at ]TK2MSFTNGP04.phx.gbl...
[Quoted Text] > Uh oh.
> I'm on the laptop now, because the desktop won't turn on. It was working
> fine, then a piece of ice from our winter weather jiggled the electrical
> lines. The house-lights flickered and the computer quit. All the
> peripherals and all the house lights are working fine. I cannot get the
> desktop computer to turn on. No indicator lights, either. Yes,
> everything was plugged into a surge protector.
>
> Is there some kind of a power connector inside the computer itself that
> may have gone out? Or have I lost my motherboard? How do I figure out
> what's broken and how to fix it?
>
> Thanks.
>
> --
>
> <*(((><
>
>
>
>
|
|
On Dec 22, 9:04 am, I_cannot_...[ at ]nowhere.net wrote:
[Quoted Text] > Everyone: ever heard of a 'crowbar' circuit?
Crowbar circuit has been standard in power supplies long before PC
even existed. It is one reason why a power supply can never damage a
motherboard. (Other functions explain why a motherboard must never
harm a power supply).
However, since so many computer assemblers have no electrical
knowledge, then a market is ripe for power supplies missing long
standard functions. A computer assemlber selecting a power supply
only on dollars and watts may then install a power supply that takes
out a motherboard and CPU. Crowbar is one reason why this must never
happen.
|
|
Hey everybody-- Great News!
I tried this suggestion first, because it was the easiest. ;-) It worked! My
desktop computer is back up and running. You folks are fantastic.
What's a Crowbar Circuit? Is that what was broken and did i/O fix it?
<*(((><
Fishy Lives!
On Mon, 22 Dec 2008 09:04:40 -0500, I_cannot_say[ at ]nowhere.net wrote:
[Quoted Text] >On Sun, 21 Dec 2008 17:28:53 -0800, "<*\(\(\(><{" <Fishy[ at ]ocean.net> wrote:
>
>>Uh oh.
>>I'm on the laptop now, because the desktop won't turn on. It was working
>>fine, then a piece of ice from our winter weather jiggled the electrical
>>lines. The house-lights flickered and the computer quit. All the
>>peripherals and all the house lights are working fine. I cannot get the
>>desktop computer to turn on. No indicator lights, either. Yes, everything
>>was plugged into a surge protector.
>>
>>Is there some kind of a power connector inside the computer itself that may
>>have gone out? Or have I lost my motherboard? How do I figure out what's
>>broken and how to fix it?
>>
>>Thanks.
>
>On the back of the power supply, where the A/C cord plugs in, is there a switch
>marked with a I and a O. If so, press the O side to shut it off and leave it that
>way for about a minute. Then, press the I side to turn it back on and see if you
>have power.
>
>Everyone: ever heard of a 'crowbar' circuit?
>
>NRJ
|
|
Crowbar: http://en.wikipedia.org/wiki/Crowbar_(circuit)
Glad you fixed it.
--
JS
http://www.pagestart.com
<*(((> wrote in message news:mhval41rnt649ma2v7hrq3b3tchpi90f03[ at ]4ax.com...
[Quoted Text] > Hey everybody-- Great News!
>
> I tried this suggestion first, because it was the easiest. ;-) It
> worked! My
> desktop computer is back up and running. You folks are fantastic.
>
> What's a Crowbar Circuit? Is that what was broken and did i/O fix it?
>
> <*(((><
> Fishy Lives!
>
>
>
>
> On Mon, 22 Dec 2008 09:04:40 -0500, I_cannot_say[ at ]nowhere.net wrote:
>
>>On Sun, 21 Dec 2008 17:28:53 -0800, "<*\(\(\(><{" <Fishy[ at ]ocean.net> wrote:
>>
>>>Uh oh.
>>>I'm on the laptop now, because the desktop won't turn on. It was working
>>>fine, then a piece of ice from our winter weather jiggled the electrical
>>>lines. The house-lights flickered and the computer quit. All the
>>>peripherals and all the house lights are working fine. I cannot get the
>>>desktop computer to turn on. No indicator lights, either. Yes,
>>>everything
>>>was plugged into a surge protector.
>>>
>>>Is there some kind of a power connector inside the computer itself that
>>>may
>>>have gone out? Or have I lost my motherboard? How do I figure out
>>>what's
>>>broken and how to fix it?
>>>
>>>Thanks.
>>
>>On the back of the power supply, where the A/C cord plugs in, is there a
>>switch
>>marked with a I and a O. If so, press the O side to shut it off and leave
>>it that
>>way for about a minute. Then, press the I side to turn it back on and see
>>if you
>>have power.
>>
>>Everyone: ever heard of a 'crowbar' circuit?
>>
>>NRJ
|
|
JS -- I read that article -- but I still don't understand what a crowbar circuit is. I'm
afraid it was too technical for me. Apparently my desktop computer has a crowbar circuit.
Is it inside the power supply, then? Does that mean it's a good quality power supply?
If anybody can figure out how to explain crowbar circuit in simple English, I'd be
appreciative.
<*(((><
Fishy Lives!
On Fri, 26 Dec 2008 21:37:16 -0500, "JS" <[ at ]> wrote:
[Quoted Text]
|
|
Fishy wrote:
[Quoted Text] > JS -- I read that article -- but I still don't understand what a crowbar circuit is. I'm
> afraid it was too technical for me. Apparently my desktop computer has a crowbar circuit.
> Is it inside the power supply, then? Does that mean it's a good quality power supply?
>
> If anybody can figure out how to explain crowbar circuit in simple English, I'd be
> appreciative.
>
> <*(((><
> Fishy Lives!
>
We can make up an example. Say your power supply has a 5V output. The
power supply monitors it. Now say something happens, and the voltage
rises to 6V. This isn't good for the computer. It expects the power
to vary by no more than 5%. So the power supply connects an artificial
internal load to the circuit. The load draws a lot of current. The power
supply has a limited output power capability. What happens then, is the
power supply detects it has an overcurrent problem, and shuts off the
switching transistors on the primary side. Now, there is no energy headed
towards the output. And the artificial load is still present, drawing
current, in case the actual source of the power lifting the 5V rail,
happens to be outside the computer. That artificial load is a "crowbar",
and only works as long as it doesn't burn out. (I built one once,
and it blew the first time I tested it :-) Very impressive.
I used an SCR and it was destroyed.)
The power supply remains "strangled" like that, until the main
power switch is turned off and on again. Turning off the power
supply, removes a low power "supervisor voltage", which the
monitoring circuitry is using. Whenever a fault happens in
the supply, they would seek to "latch" or store the fact
that the supply detected a problem, so it doesn't attempt
to start over and over again. If it was allowed to start
over and over again, it could fry something inside the
computer.
I guess my problem is, I didn't bother to suggest turning
the switch on the back of the computer from On to Off to On
again. That would be a natural first reaction to a problem,
but it never occurred to me to suggest it.
Same as checking the power cord, to make sure it is
firmly in place on the back of the power supply. There
have been several people with funny symptoms, where
reseating the cable on the back of the computer,
fixed it.
There are some computers, without a switch on the back
of them, and for those ones, you'd unplug them and
replug them in. That does the same thing as using
the switch on the back, and clears the latched fault.
If you have symptoms that suggest the power supply is damaged,
then following the above advice is a Bad Thing. For example,
if there is a strong burned smell coming from the computer,
then attempting to start it again is a bad thing to do.
I've run into the odd genius, who when faced with a computer
that protected itself, tried fifty times to start it again,
until it eventually did and it died. If the computer is
protecting itself because of an internal fault, the
protection circuits don't necessarily last forever,
or catch every fault. So if you "hammer" the power switch,
or make an ass of yourself, it can cost you $$$.
Paul
|
|
On Dec 26, 11:47 pm, Fishy <<*(((><[ at ]drift.net> wrote:
[Quoted Text] > JS -- I read that article -- but I still don't understand what a crowbar circuit is. I'm
> afraid it was too technical for me.
From Wikipedia:
> A crowbar ... is an electrical circuit used to prevent an overvoltage
> condition of a power supply unit from damaging the circuits
> attached to the power supply. It operates by putting a short circuit
> or low resistance path across the voltage source ...
What is so difficult? If a voltage is too high, its wires are
shorted together. Therefore no voltage exists and no damage results.
Paul describes this is further detail and with numbers.
All power supplies should have crowbar circuits. Its existance -
overvoltage protection - would be noted in the supply's technical
specs that are provided with any minimally sufficient supply.
A supply without overvoltage protection is typical of supplies
marketed to A+ Certified computer techs who need no electrical
konwledge to become certified.
|
|
Think of a crowbar in terms of a "circuit breaker" in your house.
The circuit breaker in your house "Trips" to the off position is you are
drawing too much current and the room goes dark.
A crowbar "Trips" when the DC voltage to PC is too high, the PC goes dark.
--
JS
http://www.pagestart.com
"Fishy" <<*((([ at ]drift.net> wrote in message
news:oncbl41s56s1tg39bqk168v14sm174tibj[ at ]4ax.com...
[Quoted Text] > > JS -- I read that article -- but I still don't understand what a crowbar > circuit is. I'm > afraid it was too technical for me. Apparently my desktop computer has a > crowbar circuit. > Is it inside the power supply, then? Does that mean it's a good quality > power supply? > > If anybody can figure out how to explain crowbar circuit in simple > English, I'd be > appreciative. > > <*(((>< > Fishy Lives! > > > > On Fri, 26 Dec 2008 21:37:16 -0500, "JS" <[ at ]> wrote: > >>Crowbar: http://en.wikipedia.org/wiki/Crowbar_(circuit)>> >>Glad you fixed it.
|
|
[Quoted Text] > A supply without overvoltage protection is typical of supplies
> marketed to A+ Certified computer techs who need no electrical
> konwledge to become certified.
Got any examples of products marketed to A+ Certified techs?
-John O
|
|
If a person says it's difficult, then it's difficult for that person. To belabor the
point might come across as a put down. Think of it this way: Tom, you use appositives on
a regular basis; you are surrounded by them. The day may come when you need to know how
to work with one. I could explain it this way:
An appositive is the result of eliminating a be-copula with its preceding relative adverb
and placing commas before and after the thus-created reduced relative phrase.
Is that so difficult?
<*(((><
Fishy Lives!
On Sat, 27 Dec 2008 07:13:23 -0800 (PST), w_tom <w_tom1[ at ]usa.net> wrote:
[Quoted Text] > What is so difficult? If a voltage is too high, its wires are
>shorted together. Therefore no voltage exists and no damage results.
>Paul describes this is further detail and with numbers.
|
|
Perfect! I've got a grasp on the concept now. Here's my next question: When the circuit
breaker trips, I reset it, then find out what caused it to trip and fix it. In my
computer, is the "crowbar" a multi-use mechanism? Or did this one event use it up, so
that I no longer have crowbar-protection on my computer?
BTW, this machine was built in 2001. I've replaced one of the hard drives and added a DVD
burner. It's still serving me well. I'll try to find the tech that built it for me and
thank him for using a good power supply with a crowbar.
<*(((><
Fishy Lives!
On Sat, 27 Dec 2008 10:51:19 -0500, "JS" <[ at ]> wrote:
[Quoted Text] >Think of a crowbar in terms of a "circuit breaker" in your house.
>The circuit breaker in your house "Trips" to the off position is you are
>drawing too much current and the room goes dark.
>A crowbar "Trips" when the DC voltage to PC is too high, the PC goes dark.
|
|
No a good power supply should be able to use the crowbar
circuit multiple times.
The real question is your surge protector any good after
"winter weather jiggled the electrical lines. ". Most surge
protectors lose their ability to stop surges over a period
on time. If it was a major surge because the electrical
line that jiggled where next to your house or just down
the street then there is a good chance that your surge
protector died in the process of trying to protect your
PC, but after it died some of the electrical surge got
through to your PCs power supply causing the
crowbar circuit to kick in.
So it may be time to replace the surge protector,
especially if your PC is working fine and the power
supply has not tripped crowbar circuit since the bad
weather incident.
--
JS
http://www.pagestart.com
"Fishy" <<*((([ at ]drift.net> wrote in message
news:cdkdl4desgmhfdpco1gm5elaenbiqrm3hi[ at ]4ax.com...
[Quoted Text] > Perfect! I've got a grasp on the concept now. Here's my next question:
> When the circuit
> breaker trips, I reset it, then find out what caused it to trip and fix
> it. In my
> computer, is the "crowbar" a multi-use mechanism? Or did this one event
> use it up, so
> that I no longer have crowbar-protection on my computer?
>
> BTW, this machine was built in 2001. I've replaced one of the hard drives
> and added a DVD
> burner. It's still serving me well. I'll try to find the tech that built
> it for me and
> thank him for using a good power supply with a crowbar.
>
> <*(((><
> Fishy Lives!
>
>
> On Sat, 27 Dec 2008 10:51:19 -0500, "JS" <[ at ]> wrote:
>
>>Think of a crowbar in terms of a "circuit breaker" in your house.
>>The circuit breaker in your house "Trips" to the off position is you are
>>drawing too much current and the room goes dark.
>>A crowbar "Trips" when the DC voltage to PC is too high, the PC goes dark.
|
|
On Dec 27, 8:12 pm, Fishy <<*(((><[ at ]drift.net> wrote:
[Quoted Text] > It's still serving me well. I'll try to find the tech that built it for me and
> thank him for using a good power supply with a crowbar.
The tech was required to use a power supply with a crowbar; as was
standard in the very first IBM PC and in computer power supplies long
before that.
If power cycling an AC switch solved that problem, a crowbar was
probably unrelated to and did nothing during the event.
Your symptoms are consistent with another completely different
function that should be in every power supply 'system'. Power supply
controller contains a safety lockout function. Depending on how power
is restored, that lockout function may be triggered. Lockout is reset
by disconnecting AC power either by unplugging or by cycling that AC
power switch.
Meanwhile, a surge would not get through a power supply and trigger
the crowbar. If a surge got through a power supply, then the power
supply was damaged AND the house is full of other damaged appliances.
Based upon your symptoms and how it was corrected, a safety lockout
circuit was triggered probably due to AC power that went off and on
repeatedly before finally staying on. Crowbar and surge protector
would both remain inert - do nothing - in that kind of event.
|
|
You guys have been so sweet! I'll get a new surge protector. I feel really lucky that my
desktop computer revived. In the meantime, however, my old laptop died. The hard drive
started clunking, and now it won't boot up; I get a message that there's no operating
system. It, too, was about 7 years old, and served me well.
<*(((><
Fishy Lives!
|
|
If you still have the Windows CD that came with
the laptop you could replace the drive. But with the cost
of the hard drive and the repair shop labor charges it may
be more advantageous to buy a new laptop.
Dell and HP have been selling some laptops for under $500.00
but stay away from the laptops that have VISTA "64 Bit"
--
JS
http://www.pagestart.com
"Fishy" <<*((([ at ]drift.net> wrote in message
news:pr6fl4tvf9p9p1584kkg1fdo6l9ms0sgte[ at ]4ax.com...
[Quoted Text] > You guys have been so sweet! I'll get a new surge protector. I feel
> really lucky that my
> desktop computer revived. In the meantime, however, my old laptop died.
> The hard drive
> started clunking, and now it won't boot up; I get a message that there's
> no operating
> system. It, too, was about 7 years old, and served me well.
>
> <*(((><
> Fishy Lives!
|
|
On Dec 28, 10:31 am, Fishy <<*(((><[ at ]drift.net> wrote:
[Quoted Text] > You guys have been so sweet! I'll get a newsurgeprotector. I feel really lucky that my
> desktopcomputerrevived. In the meantime, however, my old laptop died. The hard drive
> started clunking, and now it won't boot up; I get a message that there's no operating
> system. It, too, was about 7 years old, and served me well.
Changes are the disk drive has simply died with no relationship to
AC power.
Meanwhile, just because it is called a surge protector does not mean
it also provides surge protection. Protection is earth ground.
Protector is simply a device to connect surges to earth. But plug-in
protectors don't have that necessary earthing connection; may even
earth surges destructively through the computer.
If concerned with such AC electric anomalies (that typically occur
once every seven years), then you need one protector for everything in
the house that actually has that earthing connection. 'Whole house'
protectors are sold only by more responsible companies, are located
where your utilities enter the building, and have that short (ie 'less
than 10 foot') connection to earth.
You phone line and cable already have those protectors installed for
free. But AC electric does not until you have it installed.
Responsible names include GE, Siemens, Cutler-Hammer, Intermatic,
Leviton, Keison, Square D, and others. Not on that list are less
responsible companies such as APC, Tripplite, Belkin, and Monster
Cable. Products from the latter have no dedicated earthing wire AND
do not even claim to provide surge protection in their numeric
specifications.
Appreciate the difference between a protector and protection.
Effective protection ends up costing about $1 per protected appliance
AND actually does earth a type of surge that is destructive.
|
|
|