Computer crash

[JD]

Hi Experts,

Yesterday was a bad one for me. I added a plug from a second computer to
a robust Trip Lite Super 10 strip and a computer that was already
attached to that strip, and running, suddenly stopped working. I tried
it in another socket but still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling Silencer 600w and very
robust.

I have a tester unit that supposedly checks power supplies when I remove
the cable connection from the mother board and then attach the tester
to that connection. It showed a green light indicating that the supply
is ok. I replaced that PS with another one that also tested ok but it
could not start the computer either. There is no light at all on the
mother board.

I suspect there may be a short in the Tripp Lite.

Suggestions please.

TIA

 

[JD]

An outlet tester, is one way to quantify what is happening on an
outlet like on your Tripplite. These are good, when you suspect a
previous home owner tried their hand at outlet wiring. The label
has a list of test results to compare to.

http://www.delstat.com/images/Outlet_Tester.jpg

The Tripplite may have a "breaker button" on the strip, which
opens if there is an overload. You have to push the button or the like,
to reset it.

And plugging the power supply right into the wall,
is another test case to try, as Philo suggested.
Take the Tripplite right out of the picture.

Some motherboards, like Asus brand, have a green LED on the
motherboard that is connected to +5VSB. The power supply
consists of two sections, the +5VSB supply, and the "main
rails" supply. You can verify that +5VSB is flowing, by
seeing the green LED glowing. The computer cannot switch
on via the front button, unless the +5VSB is working. So no
matter how you do it, the availability of +5VSB from the
supply to the motherboard, is a precondition for success.
If the motherboard is some other brand, you may need a
multimeter to probe the +5VSB wire on the power supply
main cable. In some cases, it can even be the silly
button on the front of the computer case, that is broken.
Those switches can be pretty cheap. The switch function
is "momentary contact", and it is up to motherboard
logic to latch the pulse from the switch. If the switch
is completely open circuit, there'll be no pulse when
you press it.

Paul

Thank you Philo, VanguardLH and Paul.

I am on the run at present and this is a short response.

First, the strip is ok. I checked all the sockets with a lamp
and all are continuous at least. I am using another (older) computer
and other components in the strip at present and all are working fine.
I did pull the power cable of the seemingly dead computer out of the
strip and used it in a wall socket - still dead. The motherboard is an
Intel D845GEBV2.

Ironically the older backup computer, that I am now using, dates back to
the 1990s and the motherboard is an Intel AL440LX. This is the most
reliable computer I have ever had. I assembled it from parts that I
bought. I find it remarkably fast and very quiet - a pleasure to use.

More info soon, I hope.

Thanks again all and have a great weekend

 

[philo]

Hi Experts,

Yesterday was a bad one for me. I added a plug from a second computer to
a robust Trip Lite Super 10 strip and a computer that was already
attached to that strip, and running, suddenly stopped working. I tried
it in another socket but still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling Silencer 600w and very
robust.

I have a tester unit that supposedly checks power supplies when I remove
the cable connection from the mother board and then attach the tester to
that connection. It showed a green light indicating that the supply is
ok. I replaced that PS with another one that also tested ok but it could
not start the computer either. There is no light at all on the mother
board.

I suspect there may be a short in the Tripp Lite.

Suggestions please.

TIA

then bypass it

 

[Paul]

Hi Experts,

Yesterday was a bad one for me. I added a plug from a second computer to
a robust Trip Lite Super 10 strip and a computer that was already
attached to that strip, and running, suddenly stopped working. I tried
it in another socket but still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling Silencer 600w and very
robust.

I have a tester unit that supposedly checks power supplies when I remove
the cable connection from the mother board and then attach the tester
to that connection. It showed a green light indicating that the supply
is ok. I replaced that PS with another one that also tested ok but it
could not start the computer either. There is no light at all on the
mother board.

I suspect there may be a short in the Tripp Lite.

Suggestions please.

TIA

An outlet tester, is one way to quantify what is happening on an
outlet like on your Tripplite. These are good, when you suspect a
previous home owner tried their hand at outlet wiring. The label
has a list of test results to compare to.

http://www.delstat.com/images/Outlet_Tester.jpg

The Tripplite may have a "breaker button" on the strip, which
opens if there is an overload. You have to push the button or the like,
to reset it.

And plugging the power supply right into the wall,
is another test case to try, as Philo suggested.
Take the Tripplite right out of the picture.

Some motherboards, like Asus brand, have a green LED on the
motherboard that is connected to +5VSB. The power supply
consists of two sections, the +5VSB supply, and the "main
rails" supply. You can verify that +5VSB is flowing, by
seeing the green LED glowing. The computer cannot switch
on via the front button, unless the +5VSB is working. So no
matter how you do it, the availability of +5VSB from the
supply to the motherboard, is a precondition for success.
If the motherboard is some other brand, you may need a
multimeter to probe the +5VSB wire on the power supply
main cable. In some cases, it can even be the silly
button on the front of the computer case, that is broken.
Those switches can be pretty cheap. The switch function
is "momentary contact", and it is up to motherboard
logic to latch the pulse from the switch. If the switch
is completely open circuit, there'll be no pulse when
you press it.

Paul

 

[VanguardLH]

Yesterday was a bad one for me. I added a plug from a second computer to
a robust Trip Lite Super 10 strip and a computer that was already
attached to that strip, and running, suddenly stopped working. I tried
it in another socket but still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling Silencer 600w and very
robust.

I have a tester unit that supposedly checks power supplies when I remove
the cable connection from the mother board and then attach the tester
to that connection. It showed a green light indicating that the supply
is ok. I replaced that PS with another one that also tested ok but it
could not start the computer either. There is no light at all on the
mother board.

I suspect there may be a short in the Tripp Lite.

And if you plug the problematic computer directly into a wall socket
(with nothing else plugged in the other paired wall socket) does that
computer work okay? Use a heavy-duty (15A) extension cord if you must
if the computer power cord doesn't reach a wall socket because you were
using the power strip's power cord to make up the distance. Surge
protection works by sacrificing themself so eventually you'll have to
replace it.

Testers are often limited in what they check. Do you know that it tests
both the +5V and +12V lines? How does it check the separate +5VSB
(standby) line that only goes to the motherboard? Does the tester
place, at least, a 10W load on the PSU to emulate some load on the PSU
(to ensure the PSU will turn on)?

With the power cord connected to computer and a *live* wall socket (and
NOT through the power strip), the PSU should be generating the 5VSB line
which is used by the on-board power circuit (for ATX hosts, power is
soft-controlled, not hardwired to the front panel Power switch). Often
there is an LED on the motherboard to indicate the 5VSB line is alive.
However, since you never described the make and model of your
motherboard, no one knows if you have an old host using the old AT-style
power circuit (from power button to PSU) or the new ATX-style power
circuit (power button to mobo and to the onboard power circuit using
5VSB).

If you have some "tester" for the PSU, why don't you have somewhere a
voltmeter (or digital meter) to check the computer end of the power cord
to see if there is AC voltage available there?

Obviously the power strip is not essential to the power feed to the
computer so get it out of the path from wall to computer and retest.
Presumably you already know whether or not the wall outlet has power by
simply plugging in a table lamp.

 

[VanguardLH]

Removing the surge/power strip from the equation.

Have you checked if the CPU fan starts to spin when you press the power
button?

Do you hear the hard drive spin up to make a whine noise?

Switches go bad. Did you remove the 2-pin wire harness from the power
button to the 2-pin header on the motherboard and simply momentarily
short the pins to see if the computer powers up?

 

[Tinkerer]

Hi Experts,

Yesterday was a bad one for me. I added a plug from a second computer to a
robust Trip Lite Super 10 strip and a computer that was already attached
to that strip, and running, suddenly stopped working. I tried it in
another socket but still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling Silencer 600w and very
robust.

I have a tester unit that supposedly checks power supplies when I remove
the cable connection from the mother board and then attach the tester to
that connection. It showed a green light indicating that the supply is ok.
I replaced that PS with another one that also tested ok but it could not
start the computer either. There is no light at all on the mother board.

I suspect there may be a short in the Tripp Lite.

Suggestions please.

A friend has an elderly Dell PC and the exact same thing happened. Totally
dead, not even the power supply fan was running. Fortunately he had the
original handbook and we looked in the troubleshooting section. It advised
removing, and then reinserting, the memory modules. We thought that
sounded a bit far fetched but we did it and ever since it has fired up
perfectly. Not saying it will work for you but easy enough to try.

 

[Strobe]

Hi Experts,

Yesterday was a bad one for me. I added a plug from a second computer to
a robust Trip Lite Super 10 strip and a computer that was already
attached to that strip, and running, suddenly stopped working. I tried
it in another socket but still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling Silencer 600w and very
robust.

I have a tester unit that supposedly checks power supplies when I remove
the cable connection from the mother board and then attach the tester
to that connection. It showed a green light indicating that the supply
is ok. I replaced that PS with another one that also tested ok but it
could not start the computer either. There is no light at all on the
mother board.

I suspect there may be a short in the Tripp Lite.

Suggestions please.

SInce the PSU itself is good, it's probably not getting the startup command
from the MB.
The front panel button or MB may have failed (your tester, of course, provides
its own startup signal to the PSU).

It could be purely coincidental that it happened when plugging in the other PC.
I hate it when that happens - over the years, it's made me waste hours chasing
wild geese.

 

[JD]

now that the power strip has been seen no to be faulty

try resetting the bios

Thanks again guys for all your help.

I revisited that computer with the Silencer power supply (ps)and found
some odd things. First, my tester indicated that the main supply from
the ps to the motherboard was ok - green light. Then I noticed that the
fan was not running. I tried the ps in several electric outlets away
from the strip and there was no response. I also used my multimeter on
the 2x2 connection (4 contacts) that gets connected to the board near
the CPU. All contacts were dead. I opened up the ps to check if there
were blown fuses. It is very hard to see everything there but I saw no
trace of a fuse. This ps has a 5-year warranty and there is at least 3
years to go.
The Intel D845 board needs unusual plugs from the power supply - I have
several Enlights but none has the 2x2 connection.

Now, while this project is developing I have another - to revamp my
older AL440 box and get it into a circuit with a new (Samsung) NetBook,
a new D-Link router, and a new DSL modem that I bought recently to
replace my dead Siemens Speedstream 4100 - well, it's alive apart from
the DSL light. ;-) Will start this project with a new thread. My
toughest problem will be dealing with Windows 7 (stripped!). I have been
using Win2K for over 10 years and, from what I have seen so far, the 7
or even a stripped 7, will be quite a change.

Have a great weekend

 

[JD]

SInce the PSU itself is good, it's probably not getting the startup command
from the MB.
The front panel button or MB may have failed (your tester, of course, provides
its own startup signal to the PSU).

It could be purely coincidental that it happened when plugging in the other PC.
I hate it when that happens - over the years, it's made me waste hours chasing
wild geese.

Thanks again guys for all your help.

I revisited that computer with the Silencer power supply (ps)and found
some odd things. First, my tester indicated that the main supply from
the ps to the motherboard was ok - green light. Then I noticed that the
fan was not running. I tried the ps in several electric outlets away
from the strip and there was no response. I also used my multimeter on
the 2x2 connection (4 contacts) that gets connected to the board near
the CPU. All contacts were dead. I opened up the ps to check if there
were blown fuses. It is very hard to see everything there but I saw no
trace of a fuse. This ps has a 5-year warranty and there is at least 3
years to go.
The Intel D845 board needs unusual plugs from the power supply - I have
several Enlights but none has the 2x2 connection.

Now, while this project is developing I have another - to revamp my
older AL440 box and get it into a circuit with a new (Samsung) NetBook,
a new D-Link router, and a new DSL modem that I bought recently to
replace my dead Siemens Speedstream 4100 - well, it's alive apart from
the DSL light. ;-) Will start this project with a new thread. My
toughest problem will be dealing with Windows 7 (stripped!). I have been
using Win2K for over 10 years and, from what I have seen so far, the 7
or even a stripped 7, will be quite a change.

Have a great weekend

 

[Paul]

Thanks again guys for all your help.

I revisited that computer with the Silencer power supply (ps)and found
some odd things. First, my tester indicated that the main supply from
the ps to the motherboard was ok - green light. Then I noticed that the
fan was not running. I tried the ps in several electric outlets away
from the strip and there was no response. I also used my multimeter on
the 2x2 connection (4 contacts) that gets connected to the board near
the CPU. All contacts were dead. I opened up the ps to check if there
were blown fuses. It is very hard to see everything there but I saw no
trace of a fuse. This ps has a 5-year warranty and there is at least 3
years to go.
The Intel D845 board needs unusual plugs from the power supply - I have
several Enlights but none has the 2x2 connection.

Now, while this project is developing I have another - to revamp my
older AL440 box and get it into a circuit with a new (Samsung) NetBook,
a new D-Link router, and a new DSL modem that I bought recently to
replace my dead Siemens Speedstream 4100 - well, it's alive apart from
the DSL light. ;-) Will start this project with a new thread. My
toughest problem will be dealing with Windows 7 (stripped!). I have been
using Win2K for over 10 years and, from what I have seen so far, the 7
or even a stripped 7, will be quite a change.

Have a great weekend

When you say "tester", it isn't clear what kind of tester that is.
That could be a device that plugs into the main power connector,
shorts PS_ON# to COM, uses window comparators on the main supply
voltage rails, and tells you whether each rail is within +/- 5%
of the right value.

A multimeter does simple things, like measure one voltage at a time.
It is a general purpose tester. It isn't that specific for power
supplies, and may need some other things connected to the supply
to make a test setup.

To make a PSU work, away from the PC, you have to connect PS_ON# to
an adjacent COM pin with a paper clip. That will turn on all the
rails. A purpose-built tester dongle, has that connection already
in place.

Without the paper clip in place, you should be able to measure and
verify the +5VSB pin. If +5VSB is good, then you can move on to the
main rails.

With the paper clip connecting PS_ON# to COM on the main harness,
you can go about measuring +3.3, +5, +12, -12V, on the main
cable, as well as picking up the 2x2 ATX12V connector and
checking it for +12V. The fans in the computer, run from the 12V output
carried on the main connector. The CPU runs from the voltage on the
2x2 connector. The power supply fan should start to run, when the
paper clip is in place. Some supplies may choose to not run the fan
at all when they're cold, but then, as the owner of the supply, you're
probably familiar with its habits in daily usage. A change of habit
is enough to suggest something isn't working right in the supply.

Power supply specs, old ones to new ones.

http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf

http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

At least one poster, has corrected my description above, by suggesting
the power supply should have a slight "test load" connected to the supply,
when the PS_ON# jumper is in place. I have a load box I built here, which
would meet that definition, and that is what I use to ensure the power
supply stays within regulation. I've also tested a couple supplies without
a load on them, and they behaved themselves.

I know that in the past, some power supplies have had a set of
"minimum loading" current values in amperes printed on the label,
and the supply may not be guaranteed to stay within +/-5 % if that
minimum specified load is missing. About the absolute worst power supply
design I've seen, had a "minimum load" of roughly 25% of the rail capacity,
which is absurd. Many computers might not manage to present that amount of
loading in day to day usage, let alone constructing load boxes to meet the
load.

While a modern supply may not need a load to behave well (some actually have a
switchable load inside, to handle this on their own), you'll have to use your
own judgment as to whether that is necessary or a good idea or not. While I could
insist to you to "build your own load box" or "connect a couple old disk
drives you're no longer using", you'll have to decide yourself, what you want
to use. And "light bulbs" are not the best loading solution, as the
cold filament may double or triple the load current for the first few
seconds. Light bulbs are a non-linear resistor. Attempting to build a
100W load from light bulbs, might cause a 300W load for the first
few seconds. My load box uses regular power resistors I got at my local
(good) electronics store. A place like Radio Shack, wouldn't have a wide
enough selection of components, to carry good power resistors.

The power supply has one other pin of interest, which is something
like "Power Good". That is a logic level signal. The supply could be
merrily humming away, but if Power Good is not asserted, the PC won't come
out of reset, and the screen will remain black. You can check the voltage
level on that signal, just like any other wire, by using your multimeter
set to volts. The power supply specs above, will tell you whether that
signal is active high or not, in which case you'd be looking for a level
closer to 5V than to 0V.

When using the multimeter for tasks like this, I try to place the black probe,
onto a pin on an idle cable somewhere. Basically, what I suggest to you,
is don't get the tips of the red and black leads close together, because
you can short them accidentally. As part of my test procedure, first I
make sure the black lead is well away from where I'm measuring (but still
connected to a black wire or to the chassis), before starting a series of
measurements. I haven't had a short yet, by doing so.

I had a friend working in the lab with me one night, and there was a bright
flash of white light coming from his side of the lab. I ran over to see what
happened, and he'd shorted a 5V @ 100A supply to ground. The short point
was the leg of an integrated circuit. With 100A available, the leg on the
integrated circuit was vaporized instantly, leading to the burst of white light.
Very impressive, and no harm to my buddy. Some modern PC supplies
can do stuff like that too, as PC supplies are now up into the 1200W
range. So try not to get any test leads or probe tips, close together.
Either that, or as they say "pack a change of underwear" for when the
fireworks start

Paul

 

[larry moe 'n curly]

I revisited that computer with the Silencer power supply (ps)and found
some odd things. First, my tester indicated that the main supply from
the ps to the motherboard was ok - green light.

More likely, the PSU tester just indicated that each output was
putting out something at all, not that all the voltages were close
enough to specs to let the computer will run. I once tried a CompUSA
brand tester (Soyo?), and it said my PSU was fine, despite the +12V
rail not putting out enough voltage to make a hard drive spin. A
better way to test may be by plugging in an HD and shorting the green
wire on the biggest PSU connector to one of the black wires next to
it. An HD won't spin unless both the +5V and +12V rails working and
each is within 5-10% of specs. However that leaves out the +3.3V rail
(lots of chips on the mobo use it) and the +12V on the 2x2 connector
(with some PSUs, it's separate from the +12V used by the HDs).

The Intel D845 board needs unusual plugs from the power supply - I have
several Enlights but none has the 2x2 connection.

The 2x2 connection has been virtually universal for motherboards and
PSUs made in the past 5 years and is a must to make the CPU on your
mobo run. There are 2x2 adapters that plug into a 4-pin inline PATA
IDE disk drive connector, like this:

http://tinyurl.com/239ojah

http://img.alibaba.com/photo/270133129/P4-12V-4-Pin-ATX-Power-Supply-Adapter-Connector-Cable.jpg

A 600W PC Power & Cooling PSU is worth getting fixed, especially
because it can put out more power than many decent 700W PSUs.

 

[JV]

Huge thanks again Paul.

When you say "tester", it isn't clear what kind of tester that is.
That could be a device that plugs into the main power connector,
shorts PS_ON# to COM, uses window comparators on the main supply
voltage rails, and tells you whether each rail is within +/- 5%
of the right value.

The tester is a little device that I bought from
PC Power & Cooling - same company that I bought
the 600w. Silencer from. To do the test it is
attached to the main power supply plug that fits
into socket on the motherboard and has 20
connections. However, the unit has only 6 contacts
so it can't measure very accurately. It gave the
green light when the
Silencer PS was not working. I discovered that one
of my Enlights has a 2x2 plug and it is now
running the computer that the Silencer was removed
from. I will return the Silencer
because it doesn't work at present and it has far
too many fat cable connectors for my liking. The
Enlight is just right but it supports only 360Watts.

A multimeter does simple things, like measure one voltage at a time.
It is a general purpose tester. It isn't that specific for power
supplies, and may need some other things connected to the supply
to make a test setup.

I have several but haven't needed to use them very
much on computers.

To make a PSU work, away from the PC, you have to connect PS_ON# to
an adjacent COM pin with a paper clip. That will turn on all the
rails. A purpose-built tester dongle, has that connection already
in place.

Without the paper clip in place, you should be able to measure and
verify the +5VSB pin. If +5VSB is good, then you can move on to the
main rails.

With the paper clip connecting PS_ON# to COM on the main harness,
you can go about measuring +3.3, +5, +12, -12V, on the main
cable, as well as picking up the 2x2 ATX12V connector and
checking it for +12V. The fans in the computer, run from the 12V output
carried on the main connector. The CPU runs from the voltage on the
2x2 connector. The power supply fan should start to run, when the
paper clip is in place. Some supplies may choose to not run the fan
at all when they're cold, but then, as the owner of the supply, you're
probably familiar with its habits in daily usage. A change of habit
is enough to suggest something isn't working right in the supply.

Power supply specs, old ones to new ones.

http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf


http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

At least one poster, has corrected my description above, by suggesting
the power supply should have a slight "test load" connected to the supply,
when the PS_ON# jumper is in place. I have a load box I built here, which
would meet that definition, and that is what I use to ensure the power
supply stays within regulation. I've also tested a couple supplies without
a load on them, and they behaved themselves.

I know that in the past, some power supplies have had a set of
"minimum loading" current values in amperes printed on the label,
and the supply may not be guaranteed to stay within +/-5 % if that
minimum specified load is missing. About the absolute worst power supply
design I've seen, had a "minimum load" of roughly 25% of the rail capacity,
which is absurd. Many computers might not manage to present that amount of
loading in day to day usage, let alone constructing load boxes to meet the
load.

While a modern supply may not need a load to behave well (some actually
have a
switchable load inside, to handle this on their own), you'll have to use
your
own judgment as to whether that is necessary or a good idea or not.
While I could
insist to you to "build your own load box" or "connect a couple old disk
drives you're no longer using", you'll have to decide yourself, what you
want
to use. And "light bulbs" are not the best loading solution, as the
cold filament may double or triple the load current for the first few
seconds. Light bulbs are a non-linear resistor. Attempting to build a
100W load from light bulbs, might cause a 300W load for the first
few seconds. My load box uses regular power resistors I got at my local
(good) electronics store. A place like Radio Shack, wouldn't have a wide
enough selection of components, to carry good power resistors.

The power supply has one other pin of interest, which is something
like "Power Good". That is a logic level signal. The supply could be
merrily humming away, but if Power Good is not asserted, the PC won't come
out of reset, and the screen will remain black. You can check the voltage
level on that signal, just like any other wire, by using your multimeter
set to volts. The power supply specs above, will tell you whether that
signal is active high or not, in which case you'd be looking for a level
closer to 5V than to 0V.

When using the multimeter for tasks like this, I try to place the black
probe,
onto a pin on an idle cable somewhere. Basically, what I suggest to you,
is don't get the tips of the red and black leads close together, because
you can short them accidentally. As part of my test procedure, first I
make sure the black lead is well away from where I'm measuring (but still
connected to a black wire or to the chassis), before starting a series of
measurements. I haven't had a short yet, by doing so.

I had a friend working in the lab with me one night, and there was a bright
flash of white light coming from his side of the lab. I ran over to see
what
happened, and he'd shorted a 5V @ 100A supply to ground. The short point
was the leg of an integrated circuit. With 100A available, the leg on the
integrated circuit was vaporized instantly, leading to the burst of
white light.
Very impressive, and no harm to my buddy. Some modern PC supplies
can do stuff like that too, as PC supplies are now up into the 1200W
range. So try not to get any test leads or probe tips, close together.
Either that, or as they say "pack a change of underwear" for when the
fireworks start

Paul

Thank you Paul for this great list of information.
I will copy and use it whenever I get into another
hole.

I'm very happy now to have the computer with the
D845 board running again. I wanted
to use it in the 2-computer (or more later) LAN I
am setting up. After the Silencer was silenced I
had to fall back on Box2 - with the AL44LX. Sadly,
that one died last night. I took all the
components out and replaced them but still no
spark of life. However, the motherboard did have
a long life - about 15 years.

I have another project to set up a LAN and I
thought I was making great strides when I had a
computer and the NetBook connected to the 'net.
There is a lot more to it than I thought, so that
is my next task.

Thanks again and have a great week

 

[JD]

plug from a second computer to a robust Trip Lite
Super 10 strip and a computer that was already
attached to that strip, and running, suddenly
stopped working. I tried it in another socket but
still no start. The power supply for this
apparently-dead computer is a PC Power & Cooling
Silencer 600w and very robust.power supplies when I remove the cable connection
from the mother board and then attach the tester
to that connection. It showed a green light
indicating that the supply is ok. I replaced that
PS with another one that also tested ok but it
could not start the computer either. There is no
light at all on the mother board.power supply (ps)and found some odd things. First,
my tester indicated that the main supply from the
ps to the motherboard was ok - green light. Then I
noticed that the fan was not running. I tried the
ps in several electric outlets away from the strip
and there was no response. I also used my
multimeter on the 2x2 connection (4 contacts) that
gets connected to the board near the CPU. All
contacts were dead. I opened up the ps to check if
there were blown fuses. It is very hard to see
everything there but I saw no trace of a fuse.
This ps has a 5-year warranty and there is at
least 3 years to go.the power supply - I have several Enlights but
none has the 2x2 connection.another - to revamp my older AL440 box and get it
into a circuit with a new (Samsung) NetBook, a new
D-Link router, and a new DSL modem that I bought
recently to replace my dead Siemens Speedstream
4100 - well, it's alive apart from the DSL light.
;-) Will start this project with a new thread. My
toughest problem will be dealing with Windows 7
(stripped!). I have been using Win2K for over 10
years and, from what I have seen so far, the 7 or
even a stripped 7, will be quite a change.
Huge thanks again Paul.

When you say "tester", it isn't clear what kind of tester that is.
That could be a device that plugs into the main power connector,
shorts PS_ON# to COM, uses window comparators on the main supply
voltage rails, and tells you whether each rail is within ± 5%
of the right value.

The tester is a little device that I bought from
PC Power & Cooling - same company that I bought
the 600w. Silencer from. To do the test it is
attached to the main power supply plug that fits
into socket on the motherboard and has 20
connections. However, the unit has only 6 contacts
so it can't measure very accurately. It gave the
green light when the
Silencer PS was not working. I discovered that one
of my Enlights has a 2x2 plug and it is now
running the computer that the Silencer was removed
from. I will return the Silencer
because it doesn't work at present and it has far
too many fat cable connectors for my liking. The
Enlight is just right but it supports only 360Watts.

A multimeter does simple things, like measure one voltage at a time.
It is a general purpose tester. It isn't that specific for power
supplies, and may need some other things connected to the supply
to make a test setup.

I have several but haven't needed to use them very
much on computers.

To make a PSU work, away from the PC, you have to connect PS_ON# to
an adjacent COM pin with a paper clip. That will turn on all the
rails. A purpose-built tester dongle, has that connection already
in place.

Without the paper clip in place, you should be able to measure and
verify the +5VSB pin. If +5VSB is good, then you can move on to the
main rails.

With the paper clip connecting PS_ON# to COM on the main harness,
you can go about measuring +3.3, +5, +12, -12V, on the main
cable, as well as picking up the 2x2 ATX12V connector and
checking it for +12V. The fans in the computer, run from the 12V output
carried on the main connector. The CPU runs from the voltage on the
2x2 connector. The power supply fan should start to run, when the
paper clip is in place. Some supplies may choose to not run the fan
at all when they're cold, but then, as the owner of the supply, you're
probably familiar with its habits in daily usage. A change of habit
is enough to suggest something isn't working right in the supply.

Power supply specs, old ones to new ones.

http://web.archive.org/web/20030424...org/developer/specs/atx/ATX_ATX12V_PS_1_1.pdf
http://www.formfactors.org/developer/specs/atx/ATX12V_1_3dg.pdf
http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

At least one poster, has corrected my

description above, by suggesting

the power supply should have a slight "test load" connected to the supply,
when the PS_ON# jumper is in place. I have a load box I built here, which
would meet that definition, and that is what I use to ensure the power
supply stays within regulation. I've also

tested a couple supplies without

a load on them, and they behaved themselves.

I know that in the past, some power supplies have had a set of
"minimum loading" current values in amperes printed on the label,
and the supply may not be guaranteed to stay within ±5 % if that
minimum specified load is missing. About the absolute worst power supply
design I've seen, had a "minimum load" of

roughly 25% of the rail capacity,

which is absurd. Many computers might not

manage to present that amount of

loading in day to day usage, let alone

constructing load boxes to meet the

load.

While a modern supply may not need a load to

behave well (some actually have a

switchable load inside, to handle this on their own), you'll have to use your
own judgment as to whether that is necessary or

a good idea or not. While I could

insist to you to "build your own load box" or "connect a couple old disk
drives you're no longer using", you'll have to decide yourself, what you want
to use. And "light bulbs" are not the best loading solution, as the
cold filament may double or triple the load current for the first few
seconds. Light bulbs are a non-linear resistor. Attempting to build a
100W load from light bulbs, might cause a 300W load for the first
few seconds. My load box uses regular power resistors I got at my local
(good) electronics store. A place like Radio Shack, wouldn't have a wide
enough selection of components, to carry good power resistors.

The power supply has one other pin of interest, which is something
like "Power Good". That is a logic level signal. The supply could be
merrily humming away, but if Power Good is not asserted, the PC won't come
out of reset, and the screen will remain black. You can check the voltage
level on that signal, just like any other wire, by using your multimeter
set to volts. The power supply specs above, will tell you whether that
signal is active high or not, in which case you'd be looking for a level
closer to 5V than to 0V.

When using the multimeter for tasks like this,

I try to place the black probe,

onto a pin on an idle cable somewhere.

Basically, what I suggest to you,

is don't get the tips of the red and black leads close together, because
you can short them accidentally. As part of my test procedure, first I
make sure the black lead is well away from where I'm measuring (but still
connected to a black wire or to the chassis), before starting a series of
measurements. I haven't had a short yet, by doing so.

I had a friend working in the lab with me one night, and there was a bright
flash of white light coming from his side of

the lab. I ran over to see what

happened, and he'd shorted a 5V @ 100A supply to ground. The short point
was the leg of an integrated circuit. With 100A available, the leg on the
integrated circuit was vaporized instantly,

leading to the burst of white light.

Very impressive, and no harm to my buddy. Some modern PC supplies
can do stuff like that too, as PC supplies are now up into the 1200W
range. So try not to get any test leads or probe tips, close together.
Either that, or as they say "pack a change of underwear" for when the
fireworks start

Paul

Thank you Paul for this great list of information.
I will copy and use it whenever I get into another
hole.

I'm very happy now to have the computer with the
D845 board running again. I wanted
to use it in the 2-computer (or more later) LAN I
am setting up. After the Silencer was silenced I
had to fall back on Box2 - with the AL44LX. Sadly,
that one died last night. I took all the
components out and replaced them but still no
spark of life. However, the motherboard did have
a long life - about 15 years.

I have another project to set up a LAN and I
thought I was making great strides when I had a
computer and the NetBook connected to the 'net.
There is a lot more to it than I thought, so that
is my next task.

Thanks again and have a great week

 

[JD]

More likely, the PSU tester just indicated that each output was
putting out something at all, not that all the voltages were close
enough to specs to let the computer will run. I once tried a CompUSA
brand tester (Soyo?), and it said my PSU was fine, despite the +12V
rail not putting out enough voltage to make a hard drive spin.

My tester has only 6 contacts and the plug has 20.
No wonder that it
gives false results.

A
better way to test may be by plugging in an HD and shorting the green
wire on the biggest PSU connector to one of the black wires next to
it. An HD won't spin unless both the +5V and +12V rails working and
each is within 5-10% of specs. However that leaves out the +3.3V rail
(lots of chips on the mobo use it) and the +12V on the 2x2 connector
(with some PSUs, it's separate from the +12V used by the HDs).


The 2x2 connection has been virtually universal for motherboards and
PSUs made in the past 5 years and is a must to make the CPU on your
mobo run. There are 2x2 adapters that plug into a 4-pin inline PATA
IDE disk drive connector, like this:

http://tinyurl.com/239ojah

http://img.alibaba.com/photo/270133129/P4-12V-4-Pin-ATX-Power-Supply-Adapter-Connector-Cable.jpg

I discovered that one of the Enlights has the 2x2
plug and it is now in
my present computer - replacing the dead 600W
Silencer. I didn't really like
that ps because of the thick cables and far more
of them than I needed.
I did like its quietness though. The Enlight is
360W - a little small but it
will probably work ok.

A 600W PC Power & Cooling PSU is worth getting fixed, especially
because it can put out more power than many decent 700W PSUs.

It's not working, so I'm sending it back to PC Power.

Thanks for your contribution Larry Moe 'n Curly

and have a great week

 

[JD]

This crash has left me with another problem.

The Silencer has a few ATA connections and lots of
IDEs. That was convenient for the only internal
ATA drive I have. My present Enlight ps has only
IDE connections. I could put the SATA drive into
an external case and use it in that way but I had
bad experiences with that before. I had to reboot
very often to find it on my screen. Is there any
such thing as a small plugin device to a PCI or
USB source that would provide the power for this
internal ATA drive.

TIA

 

[Paul]

This crash has left me with another problem.

The Silencer has a few ATA connections and lots of IDEs. That was
convenient for the only internal ATA drive I have. My present Enlight ps
has only IDE connections. I could put the SATA drive into an external
case and use it in that way but I had bad experiences with that before.
I had to reboot very often to find it on my screen. Is there any such
thing as a small plugin device to a PCI or USB source that would provide
the power for this internal ATA drive.

TIA

Do you mean one of these ?

"Molex 4-pin Male to 15-pin SATA Power Cable"

http://www.newegg.com/Product/Product.aspx?Item=N82E16812186043

They also make "Y" cable versions, with male and female Molex, so
you can chain adapters together.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812123120

The Molex has good current carrying capacity, which is why it
makes a good candidate for chaining. The SATA on the other hand,
is lacking in that department. If a power supply had only
SATA power connectors on it, you'd be in some difficulty getting
power for accessories. I've had three or four Molex Y cables in a chain,
to power things like fans, video card aux connector, disk drives
and so on. So for me, chaining does come in handy.

Paul

 

[JD]

Do you mean one of these ?

"Molex 4-pin Male to 15-pin SATA Power Cable"

http://www.newegg.com/Product/Product.aspx?Item=N82E16812186043

They also make "Y" cable versions, with male and female Molex, so
you can chain adapters together.

http://www.newegg.com/Product/Product.aspx?Item=N82E16812123120

The Molex has good current carrying capacity, which is why it
makes a good candidate for chaining. The SATA on the other hand,
is lacking in that department. If a power supply had only
SATA power connectors on it, you'd be in some difficulty getting
power for accessories. I've had three or four Molex Y cables in a chain,
to power things like fans, video card aux connector, disk drives
and so on. So for me, chaining does come in handy.

Paul

Thanks Paul for your help. You probably know by
now that I found the connector
to link the SATA drive to the power supply. What a
relief!