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Skybuck
June 9th 07, 05:11 AM
Hello,

Some have suggested to buy a voltmeter and then test the power supply.

Since computers have special plugs and such, how would one go about
testing the power supply ?

Are there special plugs necessary ?

(Not that I would ever try it, way to dangerous !)

Do you have a link to a website with some pictures ?

Bye,
Skybuck.

Inglo
June 9th 07, 06:33 AM
Skybuck wrote:
> Hello,
>
> Some have suggested to buy a voltmeter and then test the power supply.
>
> Since computers have special plugs and such, how would one go about
> testing the power supply ?
>
> Are there special plugs necessary ?
>
> (Not that I would ever try it, way to dangerous !)
>
> Do you have a link to a website with some pictures ?
>
> Bye,
> Skybuck.
>
>
How about buying a power supply tester, they sell them pretty cheap.

--
"Out here on the perimeter there are no stars"

Steve --Inglo--

Phil Weldon
June 9th 07, 08:21 AM
'Skybuck' wrote:
| Some have suggested to buy a voltmeter and then test the power supply.
|
| Since computers have special plugs and such, how would one go about
| testing the power supply ?
|
| Are there special plugs necessary ?
|
| (Not that I would ever try it, way to dangerous !)
|
| Do you have a link to a website with some pictures ?
_____

All mains voltage is contained within the metal ATX power supply box. Just
follow basic safety proceedure used when working on ANY device connected to
mains voltage (i.e. don't stick screwdrivers into the supply when it is
plugged in.)

Keep in mind that mains voltage is ALWAYS present in the ATX power supply
EVEN when the system front panel switch is turned off AND the power switch
(if any) on the back of the power supply is turned off as long is the power
cord is plugged into the mains.

The System front panel switch just handles logic level voltages. However,
you must supply a POWER ON logic level TO the power supply to get it to turn
on.

Diagrams and specifications for the ATX power supply are at
http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf .
Included are pinouts for the various power plugs.

A digital voltmeter should be used for measuring voltages.

The voltages under no load will not be representative of the voltages under
load. Voltage measurements when the system is operating are much more
useful. Thus the reason for system monitoring chips.

A good computer repair shop is recommended.

Phil Weldon

"Skybuck" > wrote in message
oups.com...
| Hello,
|
| Some have suggested to buy a voltmeter and then test the power supply.
|
| Since computers have special plugs and such, how would one go about
| testing the power supply ?
|
| Are there special plugs necessary ?
|
| (Not that I would ever try it, way to dangerous !)
|
| Do you have a link to a website with some pictures ?
|
| Bye,
| Skybuck.
|

Nonymous
June 9th 07, 04:17 PM
Skybuck > wrote in news:1181362277.933852.227520
@k79g2000hse.googlegroups.com:

> Hello,
>
> Some have suggested to buy a voltmeter and then test the power supply.
>
> Since computers have special plugs and such, how would one go about
> testing the power supply ?
>
> Are there special plugs necessary ?
>
> (Not that I would ever try it, way to dangerous !)
>
> Do you have a link to a website with some pictures ?

http://www.compusa.com/products/product_info.asp?pfp=cat3&product_code=
332184&Pn=ATX_12V_Version_2_0_Power_Supply_Tester

They have them right in the store if you have a CompUSA local to you.

martin griffith[_2_]
June 9th 07, 06:39 PM
On Fri, 08 Jun 2007 21:11:17 -0700, in sci.electronics.design Skybuck
> wrote:

>Hello,
>
>Some have suggested to buy a voltmeter and then test the power supply.
>
Make sure you get a voltmeter with a USB connector, in case you have
to reinstall the OS on the voltmeter


martin

Phil Weldon
June 9th 07, 07:12 PM
'martin' wrote:
| Make sure you get a voltmeter with a USB connector, in case you have
| to reinstall the OS on the voltmeter
_____

Actually, you CAN get Digital Multimeters with serial and USB ports - for
logging, and, I suppose, for flash updates for the more sophisticated DMMs.

Phil Weldon

"martin griffith" > wrote in message
...
| On Fri, 08 Jun 2007 21:11:17 -0700, in sci.electronics.design Skybuck
| > wrote:
|
| >Hello,
| >
| >Some have suggested to buy a voltmeter and then test the power supply.
| >
| Make sure you get a voltmeter with a USB connector, in case you have
| to reinstall the OS on the voltmeter
|
|
| martin

martin griffith[_2_]
June 9th 07, 07:26 PM
On Sat, 09 Jun 2007 18:12:43 GMT, in sci.electronics.design "Phil
Weldon" > wrote:

>'martin' wrote:
>| Make sure you get a voltmeter with a USB connector, in case you have
>| to reinstall the OS on the voltmeter
>_____
>
>Actually, you CAN get Digital Multimeters with serial and USB ports - for
>logging, and, I suppose, for flash updates for the more sophisticated DMMs.
>
>Phil Weldon
>
>"martin griffith" > wrote in message
...
>| On Fri, 08 Jun 2007 21:11:17 -0700, in sci.electronics.design Skybuck
>| > wrote:
>|
>| >Hello,
>| >
>| >Some have suggested to buy a voltmeter and then test the power supply.
>| >
>| Make sure you get a voltmeter with a USB connector, in case you have
>| to reinstall the OS on the voltmeter
>|
>|
>| martin
>
Yes I know, but considering all the problems the OP is having with
bios and stuff, I thought I would just add to his confusion


martin

Angry_American
June 10th 07, 12:37 AM
"Inglo" <[email protected]??.> wrote in message
. net...
> Skybuck wrote:
>> Hello,
>>
>> Some have suggested to buy a voltmeter and then test the power supply.
>>
>> Since computers have special plugs and such, how would one go about
>> testing the power supply ?
>>
>> Are there special plugs necessary ?
>>
>> (Not that I would ever try it, way to dangerous !)
>>
>> Do you have a link to a website with some pictures ?
>>
>> Bye,
>> Skybuck.
>>
>>
> How about buying a power supply tester, they sell them pretty cheap.
>


They are basically useless. The only way to fully test a PSU is under load.
If has to be plugged in and the computer needs to be running. A voltmeter is
the only way to go. Just because a PSU works when its not under load ie
using a PSU tester does not mean it wont fail under load, once its gotten
good and warm.

Dan

d.schatkamer
June 10th 07, 12:43 AM
"Angry_American" > schreef in bericht
g.com...
> "Inglo" <[email protected]??.> wrote in message
> . net...
>> Skybuck wrote:
>>> Hello,
>>>
>>> Some have suggested to buy a voltmeter and then test the power supply.
>>>
>>> Since computers have special plugs and such, how would one go about
>>> testing the power supply ?
>>>
>>> Are there special plugs necessary ?
>>>
>>> (Not that I would ever try it, way to dangerous !)
>>>
>>> Do you have a link to a website with some pictures ?
>>>
>>> Bye,
>>> Skybuck.
>>>
>>>
>> How about buying a power supply tester, they sell them pretty cheap.
>>
>
>
> They are basically useless. The only way to fully test a PSU is under
> load. If has to be plugged in and the computer needs to be running. A
> voltmeter is the only way to go. Just because a PSU works when its not
> under load ie using a PSU tester does not mean it wont fail under load,
> once its gotten good and warm.
>
> Dan

You better change your name in stupid american like the rest.
Stop crossposting !
fup set

Frank McCoy
June 10th 07, 04:41 AM
In alt.comp.hardware.pc-homebuilt "Angry_American"
> wrote:

>"Inglo" <[email protected]??.¿¿¿> wrote in message
. net...
>> Skybuck wrote:
>>> Hello,
>>>
>>> Some have suggested to buy a voltmeter and then test the power supply.
>>>
>>> Since computers have special plugs and such, how would one go about
>>> testing the power supply ?
>>>
>>> Are there special plugs necessary ?
>>>
>>> (Not that I would ever try it, way to dangerous !)
>>>
>>> Do you have a link to a website with some pictures ?
>>>
>>> Bye,
>>> Skybuck.
>>>
>>>
>> How about buying a power supply tester, they sell them pretty cheap.
>>
>
>
>They are basically useless.

I wouldn't say that.
I've replaced about a half-dozen power supplies by different makers over
the past three to four years; and *every single one* failed to properly
power-on the cheap $20 tester I have. Only GOOD PSUs brought it to
life.

>The only way to fully test a PSU is under load.

That is true ... but only "to fully test".
A Power-Supply-Tester is a handy way to check a failed supply and
confirm it has failed. Only if it says the supply is *good* and yet the
system shows signs of power-supply failure do you need more extensive
tests. When the Power-Supply-Tester fails to power-on when hooked to a
PSU, taking voltage measurements afterwards is overkill.

Just toss the thing.

And MOST bad supplies won't power up even a cheap tester.
It's quick and dirty; but definitely NOT useless.

>If has to be plugged in and the computer needs to be running. A voltmeter is
>the only way to go. Just because a PSU works when its not under load ie
>using a PSU tester does not mean it wont fail under load, once its gotten
>good and warm.
>
But if it fails the PSU tester, then why go to the bother of all the
other ****? And, in most cases of a failed supply, it WILL fail.

A HELL of a lot quicker too, than probing around with a voltmeter.
Just don't trust it to find marginal cases; or especially don't expect
it to find power supplies that were underpowered when bought; unless, of
course, the being underpowered is what caused the PSU to fail.

That's why you keep BOTH in your toolbox.

--
_____
/ ' / ™
,-/-, __ __. ____ /_
(_/ / (_(_/|_/ / <_/ <_

larry moe 'n curly
June 10th 07, 08:21 AM
Inglo wrote:

> How about buying a power supply tester, they sell them pretty cheap.

Unless it has a digital readout, it's not much good except for telling
if the PSU is completely dead or not. The one I tried said that my
PSU was fine even though the +12V rail was too low to let HDs spin.

A cheap digital multimeter and a bent paperclip to short the green
Power-On line to either of the black ground lines next to it are
usually good enough, but sometimes a couple of 10 ohm, 8-10 watt
resistors are needed to load down the +5V (connect each between a red
wire and a black wire).

default[_2_]
June 10th 07, 02:31 PM
On Fri, 08 Jun 2007 21:11:17 -0700, Skybuck >
wrote:

>Hello,
>
>Some have suggested to buy a voltmeter and then test the power supply.
>
>Since computers have special plugs and such, how would one go about
>testing the power supply ?
>
>Are there special plugs necessary ?
>
>(Not that I would ever try it, way to dangerous !)
>
>Do you have a link to a website with some pictures ?
>
>Bye,
> Skybuck.

If you don't open the case there's nothing that should bite you.

You need a "dummy load" to load down the PS to test it (many won't
even power up without a load of some sort)

None of the commercial units, I've seen, put enough load on a PS to
stress it (pulling 10 watts from a 300+ watt supply isn't a real
test).

There were some dummy load schematics on the web. What would be good
(don't know if anyone is selling it) would be a plug that can be put
between the PS connector and mobo and analyze and monitor the actual
voltages with some lights to tell you if the power is clean.

--

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