Power supply, but no power???

Thanks for the reply.

 > If the power supply is toasted, then you have an important
 > fact. What inside the power supply is blackened? However if
 >just assuming it was some surge and if assuming it was the
 > power supply, then you have much to learn.

Yes, I know the PSU is toasted. Whether or not anything else is
damaged is what I don't know. I haven't bothered opening up the power
supply itself... and other than recognizing what resistors and
capacitors are, I'm not real familiar with the components _within_ a
psu. I don't know what caused the problem, but the circuit breaker was
thrown for the entire room (not only did computer shut down, all the
lights and clocks turned off, etc). However, it wasn't a brown- or
black-out.

 > There is no faster analysis than using a 3.5 digit multimeter.
 > Two minutes should suggest what is defective.

That'll be my next step. Thanks for the info.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

Wes Newell <w.newell DeleteThis @TAKEOUTverizon.net> wrote in message news:<pan.2005.04.07.21.06.50.364178 DeleteThis @TAKEOUTverizon.net>...
 > On Thu, 07 Apr 2005 13:28:25 -0700, U. Cortez wrote:
 >
  > > I believe a power surge toasted my power supply the other day, so I
  > > replaced it with a new 350W ATX PSU. After removing the burnt psu, I
  > > screwed the new psu into the case, hooked the ATX power supply to the
  > > motherboard, and hooked up power for various components (HD's,
  > > CD-ROM's). The motherboard's pilot light turns on to signify that it's
  > > getting power, but when I press the case's power button... nothing. No
  > > fans, no sound, no disk spinning, no signs of life at all (besides that
  > > pilot light being on). Am I forgetting something?
  > >
  > > Where do I go from here? Any help would be appreciated.
  > >
 > Double check the power button plug is plugged into the proper pins. If it
 > is and it still doesn't work, unplug it and short the 2 power button pins
 > on the MB for a second. It should turn on power. If not, then it may be a
 > bad MB or bad PSU. If it does come on that way, then the problem is in the
 > leads to, or the power button itself.

try taking all of the components out of your computer and runniong the
system out of the case, at least this mught remove the chance that
something is grounded.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

If the power supply is toasted, then you have an important
fact. What inside the power supply is blackened? However if
just assuming it was some surge and if assuming it was the
power supply, then you have much to learn. The power supply
'system' is many components. A power supply is only one
part. You could swap things forever until something works.
Or discover in but two minutes what is and is not damaged.

Procedures and concepts are provided in two previous posts:
"Computer doesnt start at all" in alt.comp.hardware on 10
Jan 2004 at
<a style='text-decoration: underline;' href="http://tinyurl.com/2t69q" target="_blank">http://tinyurl.com/2t69q</a> and
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
<a style='text-decoration: underline;' href="http://tinyurl.com/yvbw9" target="_blank">http://tinyurl.com/yvbw9</a>

Just because a light is on does not mean sufficient voltage
is available. Lights can illuminate; fans spin; and still the
power supply is not working. But then a power supply might
shutdown because something else is defective. There is no
faster analysis than using a 3.5 digit multimeter. Two
minutes should suggest what is defective. Furthermore,
numbers that mean nothing to you could be the 'smoking gun'
solution for those with better knowledge. Without numbers,
you cannot tap the best sources on the other side of your
computer screen.

"U. Cortez" wrote:
 > I believe a power surge toasted my power supply the other day, so I
 > replaced it with a new 350W ATX PSU. After removing the burnt psu, I
 > screwed the new psu into the case, hooked the ATX power supply to the
 > motherboard, and hooked up power for various components (HD's,
 > CD-ROM's). The motherboard's pilot light turns on to signify that it's
 > getting power, but when I press the case's power button... nothing. No
 > fans, no sound, no disk spinning, no signs of life at all (besides that
 > pilot light being on). Am I forgetting something?
 >
 > I inspected all the components (and the motherboard and cpu) and none
 > of them appear (or smell) to have been damaged.
 >
 > Where do I go from here? Any help would be appreciated.
 >
 > Motherboard: DFI AK70 (AMD 750 cpu).<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

 > If the power supply is toasted, then you have an important
 > fact. What inside the power supply is blackened?

Just for kicks, I opened up the old psu and it looks like a couple
capacitors blew. I'm not going to be all that dissappointed to see
that psu taken to the morgue, as it was old and cheap and possibly
under-powered. However, I won't be a happy puppy if my motherboard got
toasted too. I'll probably test it today and see...

-U.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

The failed capacitors (and probably failed diodes) is
consistent with the circuit breaker tripping. Now here is
where we discover the technical knowledge of the guy who
selected that supply. Asian manufacturers have learned there
are many computer assemblers masguading as electrically
knowledgeable. So power supplies that are missing essential
functions are now dumped into the market at greater profit.
You know them by their lower price. These are functions where
were defacto standard even 30 years ago.

Any power supply that fails must not damage any other
computer part. But if the essential function was missing in
that supply, then you now may have other damage. A minimally
acceptable supply sells for about $65 full retail. Supplies
missing essential functions such as overvoltage protection
sell for less, earn greater profits for their manufacturers,
and can then cause disk drive and motherboard failure.

You have no other failures inside the computer IF the
original power supply was minimally acceptable; not selected
by a 'bean counting' computer assembler.

"U. Cortez" wrote:
 > Just for kicks, I opened up the old psu and it looks like a couple
 > capacitors blew. I'm not going to be all that dissappointed to see
 > that psu taken to the morgue, as it was old and cheap and possibly
 > under-powered. However, I won't be a happy puppy if my motherboard got
 > toasted too. I'll probably test it today and see...
 >
 > -U.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

On Fri, 08 Apr 2005 12:22:21 -0400, w_tom wrote:

 > Any power supply that fails must not damage any other
 > computer part. But if the essential function was missing in
 > that supply, then you now may have other damage. A minimally
 > acceptable supply sells for about $65 full retail. Supplies
 > missing essential functions such as overvoltage protection
 > sell for less, earn greater profits for their manufacturers,
 > and can then cause disk drive and motherboard failure.
 >
I think overload protection is a requirement for UL approval. And I've
never spent over $24 for a PSU.

I've used a 600W similar to this for over a year now on my A64 system. But
it was $24 when I bought mine.

<a style='text-decoration: underline;' href="http://store.mrtechus.com/60ulapatxcop.html" target="_blank">http://store.mrtechus.com/60ulapatxcop.html</a>

--
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My server <a style='text-decoration: underline;' href="http://wesnewell.no-ip.com/cpu.php" target="_blank">http://wesnewell.no-ip.com/cpu.php</a>
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 >> Stay informed about: Power supply, but no power??? 

It sounds like the power surge also toasted your motherboard. This
frequently happens when an inexpensive power supply unit is used in a
system. It passes the surge on to the motherboard, rather than absorb it
entirely.

--
DaveW



"U. Cortez" <goodbadskinnee.TakeThisOut@yahoo.com> wrote in message
news:1112905705.124652.269770@f14g2000cwb.googlegroups.com...
 >I believe a power surge toasted my power supply the other day, so I
 > replaced it with a new 350W ATX PSU. After removing the burnt psu, I
 > screwed the new psu into the case, hooked the ATX power supply to the
 > motherboard, and hooked up power for various components (HD's,
 > CD-ROM's). The motherboard's pilot light turns on to signify that it's
 > getting power, but when I press the case's power button... nothing. No
 > fans, no sound, no disk spinning, no signs of life at all (besides that
 > pilot light being on). Am I forgetting something?
 >
 > I inspected all the components (and the motherboard and cpu) and none
 > of them appear (or smell) to have been damaged.
 >
 > Where do I go from here? Any help would be appreciated.
 >
 > Motherboard: DFI AK70 (AMD 750 cpu).
 >
 > -U.
 >
 > PS, forgive the cross-post -- I don't have a news host and google is
 > giving me errors when I try to post to some of these groups
 > individually.
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

Well last night I tested the power supply (with it just plugged into
the motherboard) and all the voltages were in their acceptable ranges.
So, I started to plug things back in 1 at a time, and... it all
worked! I'm typing this now on my working computer. There must have
just been a loose connection or something when I first installed my new
PSU. But when I took my computer apart (yes, I mean completely apart
-- even took the cooler off the cpu) and put it back together I must
have secured whatever was keeping it from starting up before.

So I guess the failed motherboard was a false alarm (whew!). Now the
first thing on my agenda: get a UPS so I don't have to worry about
circuit trips blowing my PSU again.

Thanks all for the help!

-U.
 >> Stay informed about: Power supply, but no power??? 

On Fri, 08 Apr 2005 17:19:23 GMT, Wes Newell
<w.newell DeleteThis @TAKEOUTverizon.net> put finger to keyboard and composed:

 >On Fri, 08 Apr 2005 12:22:21 -0400, w_tom wrote:
 >
  >> Any power supply that fails must not damage any other
  >> computer part. But if the essential function was missing in
  >> that supply, then you now may have other damage. A minimally
  >> acceptable supply sells for about $65 full retail. Supplies
  >> missing essential functions such as overvoltage protection
  >> sell for less, earn greater profits for their manufacturers,
  >> and can then cause disk drive and motherboard failure.
  >>
 >I think overload protection is a requirement for UL approval. And I've
 >never spent over $24 for a PSU.
 >
 >I've used a 600W similar to this for over a year now on my A64 system. But
 >it was $24 when I bought mine.

 >http://store.mrtechus.com/60ulapatxcop.html

I'd be suspicious of that 600W rating. The combined output of the 3
major rails is 644W, a figure that doesn't appear to allow for proper
derating. If it's a Deer brand PSU, I'd be looking especially closely
at it. I've been stung by a 170W fake labelled as 400W.

Here are the claimed specs from the above URL:

===================================================================
ATX 600 Watt Power Supply for P4 ,PIII and AMD processor compatible
with ATX 2.03 standard.

DC Output:

+5V 50A +/-5% +3.3V 32A +/-4% +12V 24A +/-5%

-12V 1.0A +/-10% -5V 0.5A +/-10% +5Vsb 2.0A +/-5%
===================================================================

Having said the above, I'd be willing to bet that the PSU in a typical
system is never called upon to provide more than about 150W.

Until my recent experience with the fake PSU, I've always been well
served by generics. In fact, I contacted a dozen or so computer stores
in my area and was unable to find a single vendor who could supply
anything other than a generic ATX PSU. Most were selling Deers. I had
to go online to find a branded PSU.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

Overvoltage protection is not required for UL approval -
obviously.

First, power supplies selling for $25 retail would quickly
forget that essential function. If is contains essential
functions such as overvoltage protection, then the
manufacturer would proudly note that function - and many
others. If is does not list overvoltage protection (as with
most sub $40 supplies), then it will also forget to install
overvoltage protection and many other essential functions.

Second, just not possible to sell a supply at $25 retail,
earn a profit, and include essential functions.

Third, UL only cares about you getting hurt. UL does not
care for an instant how destructive that power supply is to
any transistors. Overvoltage protection does nothing for
human safety.

Fourth, then there is the common problem with counterfeit UL
stickers. No way a $25 supply is going to include functions
considered essential even 30 years ago.

Wes Newell wrote:
 > On Fri, 08 Apr 2005 12:22:21 -0400, w_tom wrote:
  >> Any power supply that fails must not damage any other
  >> computer part. But if the essential function was missing in
  >> that supply, then you now may have other damage. A minimally
  >> acceptable supply sells for about $65 full retail. Supplies
  >> missing essential functions such as overvoltage protection
  >> sell for less, earn greater profits for their manufacturers,
  >> and can then cause disk drive and motherboard failure.
 >
 > I think overload protection is a requirement for UL approval. And I've
 > never spent over $24 for a PSU.
 >
 > I've used a 600W similar to this for over a year now on my A64
 > system. But it was $24 when I bought mine.
 >
<font color=purple> > <a style='text-decoration: underline;' href="http://store.mrtechus.com/60ulapatxcop.html</font" target="_blank">http://store.mrtechus.com/60ulapatxcop.html</font</a>><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

Problem could even been created by a motherboard standoff
shorted through solder mask. Example of why one does not swap
parts. You fixed (permanently or temporarily) the problem and
don't even know why it existed. In the future, get the
numbers before disassembling anything. At least we would have
a much short list of suspects. If failure is seen on meter,
then you could disconnect some things and test until the
problem is resolved. Knowing which voltage was problematic
could have also been more helpful.

Just a better way to approach the problem next time.
Historically, such intermittents tend to return slightly more
often than not.

"U. Cortez" wrote:
 > Well last night I tested the power supply (with it just plugged into
 > the motherboard) and all the voltages were in their acceptable ranges.
 > So, I started to plug things back in 1 at a time, and... it all
 > worked! I'm typing this now on my working computer. There must have
 > just been a loose connection or something when I first installed my new
 > PSU. But when I took my computer apart (yes, I mean completely apart
 > -- even took the cooler off the cpu) and put it back together I must
 > have secured whatever was keeping it from starting up before.
 >
 > So I guess the failed motherboard was a false alarm (whew!). Now the
 > first thing on my agenda: get a UPS so I don't have to worry about
 > circuit trips blowing my PSU again.
 >
 > Thanks all for the help!
 >
 > -U.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Power supply, but no power??? 

On Sun, 10 Apr 2005 06:07:31 -0400, w_tom wrote:

 > Overvoltage protection is not required for UL approval -
 > obviously.
 >
If you say so.
 >
 > Second, just not possible to sell a supply at $25 retail,
 > earn a profit, and include essential functions.
 >
So, you don't think they could spent an extra 25 cents to do this in a $25
PSU. Interesting.

 > Third, UL only cares about you getting hurt. UL does not
 > care for an instant how destructive that power supply is to any
 > transistors. Overvoltage protection does nothing for human safety.
 >
Again, if you say so.

 > Fourth, then there is the common problem with counterfeit UL
 > stickers. No way a $25 supply is going to include functions considered
 > essential even 30 years ago.
 >
Well, This psu says it has overload protection, and I have no basis for
calling them liars. It's retail price is over $40, but it's sale price is
only $18. They also have a 300W unit that states it has overload
protection they sell for $9 (Retail price of $24).

<a style='text-decoration: underline;' href="http://store.mrtechus.com/60ulapatxcop.html" target="_blank">http://store.mrtechus.com/60ulapatxcop.html</a>

--
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My server <a style='text-decoration: underline;' href="http://wesnewell.no-ip.com/cpu.php" target="_blank">http://wesnewell.no-ip.com/cpu.php</a>
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 >> Stay informed about: Power supply, but no power??? 

I think you both have a point. I have no doubt that there are cheap
psu's out there that completely ignore the need for overvoltage
protection. On the contrary, there are probably some inexpensive psu's
that have the protection. While it appears that the psu that wes found
does have protection, I'd still be a little skeptical of a psu that
claims to push 600w but only cost $18. Personally, I'll stick with
name-brand psu's.
 >> Stay informed about: Power supply, but no power???