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Power Supply Tester

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Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 6:04:19 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

All,

I have been working on this pc, (Dell Dimension 2300 2 GHz, 256 MB, 40 GB),
and despite being only 2 - 3 years old, the inside was filthy. I cleaned it
out very well with compressed air, afterward, it would not start, and in
fact, would turn slightly( the fans would move), just by plugging it in.
After I took it apart and re-cleaned everything, I was able to get the pc to
turn on normally. I reimaged, and everything appears to be fine, However,
today I borrowed a power supply tester, and when I tested it, one of the 5
volt lights does not come on, (the - 5V), and overall, both the "good" light
and the 'danger' light come on.
Does this mean that the power supply is bad? The computer seems to be
running fine now.


RF

More about : power supply tester

August 1, 2004 6:04:20 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Could be getting ready to go....I would leave it on for a long time and see
if it starts rebooting.

--
Mark
MCSA, CNA, A+, Net+, iNet+, Server+
"RF" <glassless2003@yahoo.com> wrote in message
news:D cYOc.189960$a24.105834@attbi_s03...
> All,
>
> I have been working on this pc, (Dell Dimension 2300 2 GHz, 256 MB, 40
GB),
> and despite being only 2 - 3 years old, the inside was filthy. I cleaned
it
> out very well with compressed air, afterward, it would not start, and in
> fact, would turn slightly( the fans would move), just by plugging it in.
> After I took it apart and re-cleaned everything, I was able to get the pc
to
> turn on normally. I reimaged, and everything appears to be fine, However,
> today I borrowed a power supply tester, and when I tested it, one of the 5
> volt lights does not come on, (the - 5V), and overall, both the "good"
light
> and the 'danger' light come on.
> Does this mean that the power supply is bad? The computer seems to be
> running fine now.
>
>
> RF
>
>
Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 6:04:20 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

RF wrote:
> All,
>
> I have been working on this pc, (Dell Dimension 2300 2 GHz, 256 MB, 40 GB),
> and despite being only 2 - 3 years old, the inside was filthy. I cleaned it
> out very well with compressed air, afterward, it would not start, and in
> fact, would turn slightly( the fans would move), just by plugging it in.
> After I took it apart and re-cleaned everything, I was able to get the pc to
> turn on normally. I reimaged, and everything appears to be fine, However,
> today I borrowed a power supply tester, and when I tested it, one of the 5
> volt lights does not come on, (the - 5V), and overall, both the "good" light
> and the 'danger' light come on.
> Does this mean that the power supply is bad? The computer seems to be
> running fine now.
>
>
> RF
>
>
The tester is more that likely for standard AT or ATX type power
supplies, however, Dell uses a proprietary power supply and the pin outs
would be different.

--
Danny Kile
Please reply to the Newsgroup ONLY

"Dogs come when they're called, CATS take a message and get back to
you." Mary Bly
Related resources
Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 6:04:20 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Howdy!

"RF" <glassless2003@yahoo.com> wrote in message
news:D cYOc.189960$a24.105834@attbi_s03...
> All,
>
> I have been working on this pc, (Dell Dimension 2300 2 GHz, 256 MB, 40
GB),
> and despite being only 2 - 3 years old, the inside was filthy. I cleaned
it
> out very well with compressed air, afterward, it would not start, and in
> fact, would turn slightly( the fans would move), just by plugging it in.
> After I took it apart and re-cleaned everything, I was able to get the pc
to
> turn on normally. I reimaged, and everything appears to be fine, However,
> today I borrowed a power supply tester, and when I tested it, one of the 5
> volt lights does not come on, (the - 5V), and overall, both the "good"
light
> and the 'danger' light come on.
> Does this mean that the power supply is bad? The computer seems to be
> running fine now.

I'd cross check - certain Dells use a non-standard wiring for the
ATX power supply, and such will require an adapter for most ATX testers to
work properly.

RwP
Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 6:04:20 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

RF wrote:

> I have been working on this pc, (Dell Dimension 2300 2 GHz, 256 MB, 40 GB),
> and despite being only 2 - 3 years old, the inside was filthy. I cleaned it
> out very well with compressed air, afterward, it would not start, and in
> fact, would turn slightly( the fans would move), just by plugging it in.
> After I took it apart and re-cleaned everything, I was able to get the pc to
> turn on normally. I reimaged, and everything appears to be fine, However,
> today I borrowed a power supply tester, and when I tested it, one of the 5
> volt lights does not come on, (the - 5V), and overall, both the "good" light
> and the 'danger' light come on.
> Does this mean that the power supply is bad? The computer seems to be
> running fine now.

The need for a -5v output on the PSU was removed from the ATX specification
in April, 2003. (ver 1.3)

http://www.formfactors.org/developer%5Cspecs%5CATX12V%2...
Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 6:07:58 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

A side note, this is a P4 power supply. I don't know if that makes a
difference or not.

Thanks,

RF
Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 8:50:44 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Sun, 01 Aug 2004 02:04:19 GMT, "RF" <glassless2003@yahoo.com>
wrote:

>All,
>
>I have been working on this pc, (Dell Dimension 2300 2 GHz, 256 MB, 40 GB),
>and despite being only 2 - 3 years old, the inside was filthy. I cleaned it
>out very well with compressed air, afterward, it would not start, and in
>fact, would turn slightly( the fans would move), just by plugging it in.
>After I took it apart and re-cleaned everything, I was able to get the pc to
>turn on normally. I reimaged, and everything appears to be fine, However,
>today I borrowed a power supply tester, and when I tested it, one of the 5
>volt lights does not come on, (the - 5V), and overall, both the "good" light
>and the 'danger' light come on.
>Does this mean that the power supply is bad? The computer seems to be
>running fine now.

-5V is irrelevant for a semi-modern PC, that voltage is "often"
still implemented on an ATX only due to spec, "true"
compatibility with some odd design never seen in typical PC. On
a Dell or any typical system not using -5V, you can completely
remove -5V line and expect no problem, other than a hardware
monitor type warning "if" that voltage is monitored at all. When
a system does not use any particular voltage rail, it is common
for that rail to be out of spec since there is no load on it,
unless the power supply itself has a built-in load, which isn't
to be expected on that rail.

Perhaps a more important question is, if everthing appears fine,
why the further testing?
Anonymous
a b B Homebuilt system
a b ) Power supply
August 1, 2004 4:20:10 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

In article <DcYOc.189960$a24.105834@attbi_s03>, RF says...

> today I borrowed a power supply tester, and when I tested it, one of the 5
> volt lights does not come on, (the - 5V), and overall, both the "good" light
> and the 'danger' light come on.
> Does this mean that the power supply is bad? The computer seems to be
> running fine now.
>
-5V is no longer used.

--
Conor

life, n.: A whim of several billion cells to be you for a while
Anonymous
a b B Homebuilt system
a b ) Power supply
August 2, 2004 7:56:42 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"RF" <glassless2003@yahoo.com> wrote in message news:<DcYOc.189960$a24.105834@attbi_s03>...

> I have been working on this pc, (Dell Dimension 2300 2 GHz,
> 256 MB, 40 GB), and despite being only 2 - 3 years old, the
> inside was filthy. I cleaned it out very well with compressed
> air, afterward, it would not start, and in fact, would turn
> slightly (the fans would move), just by plugging it in.
> After I took it apart and re-cleaned everything, I was able
> to get the pc to turn on normally. I reimaged, and everything
> appears to be fine, However, today I borrowed a power supply
> tester, and when I tested it, one of the 5 volt lights does
> not come on, (the - 5V), and overall, both the "good" light
> and the 'danger' light come on. Does this mean that the
> power supply is bad? The computer seems to be running fine now.

I have a couple of mobos made in 1997 that don't use the -5V or -12V,
so I wouldn't worry about that. But I also wouldn't trust any PSU
tester because one I borrowed said that a PSU was OK even though its
+12V rail was at about 10.5V and kept the HD from spinning. It's
better to buy a cheap digital multimeter and learn how to use it
because not only will it be a lot more accurate (2% error, worst
case), but it can be used for testing lots of other things.
August 2, 2004 3:31:39 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

larrymoencurly wrote:

> I have a couple of mobos made in 1997 that don't use the -5V or -12V,
> so I wouldn't worry about that. But I also wouldn't trust any PSU
> tester because one I borrowed said that a PSU was OK even though its
> +12V rail was at about 10.5V and kept the HD from spinning. It's
> better to buy a cheap digital multimeter and learn how to use it
> because not only will it be a lot more accurate (2% error, worst
> case), but it can be used for testing lots of other things.

Yeah I second that. A cheap tester can be $9 on sale at Radio Shack,
and blows the doors off a single-purpose tester. Even a nice meter can
be had for $40, or you can blow a week's salary on a Fluke if you like.
Having R, V, and I testing is nice, although I like capacitance
testing too. Now my question is, does the single-purpose tester put the
voltage source under load? It's possible for a supply to do well under
no load, and drop miserably under load. No supply on the planet is an
ideal voltage source.

I wonder why - 5 V is more rare? Either the - 5 V is derived from some
onboard regulator, or it's not needed. And 5 V is more for TTL, so
perhaps that's been superceded by other topologies.

michael
Anonymous
a b B Homebuilt system
a b ) Power supply
August 2, 2004 3:31:40 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Michael wrote:

> larrymoencurly wrote:
>
>> I have a couple of mobos made in 1997 that don't use the -5V or -12V,
>> so I wouldn't worry about that. But I also wouldn't trust any PSU
>> tester because one I borrowed said that a PSU was OK even though its
>> +12V rail was at about 10.5V and kept the HD from spinning. It's
>> better to buy a cheap digital multimeter and learn how to use it
>> because not only will it be a lot more accurate (2% error, worst
>> case), but it can be used for testing lots of other things.
>
>
> Yeah I second that. A cheap tester can be $9 on sale at Radio Shack,
> and blows the doors off a single-purpose tester. Even a nice meter can
> be had for $40, or you can blow a week's salary on a Fluke if you like.
> Having R, V, and I testing is nice, although I like capacitance testing
> too. Now my question is, does the single-purpose tester put the voltage
> source under load? It's possible for a supply to do well under no load,
> and drop miserably under load. No supply on the planet is an ideal
> voltage source.
>
> I wonder why - 5 V is more rare? Either the - 5 V is derived from some
> onboard regulator, or it's not needed.

It's no longer needed. Was there for older technology that needed a
negative BIAS source.

> And 5 V is more for TTL, so
> perhaps that's been superceded by other topologies.
>
> michael
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 2:08:18 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"larrymoencurly" <larrymoencurly@my-deja.com> wrote in message
news:755e968a.0408020256.2fdeb281@posting.google.com...
>
> I have a couple of mobos made in 1997 that don't use the -5V
or -12V,
> so I wouldn't worry about that. But I also wouldn't trust any PSU
> tester because one I borrowed said that a PSU was OK even though its
> +12V rail was at about 10.5V and kept the HD from spinning. It's
> better to buy a cheap digital multimeter and learn how to use it
> because not only will it be a lot more accurate (2% error, worst
> case), but it can be used for testing lots of other things.

I have to agree. I have a PSU tester and it tested a PSU as okay, but
the PSU was faulty... I learned to use my digital multimeter from now
on :-)
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 5:42:47 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Michael <none@none.com> wrote in message news:<vCpPc.6715$Jp6.6685@newsread3.news.atl.earthlink.net>...
> larrymoencurly wrote:
>
>> But I also wouldn't trust any PSU tester because one I
>> borrowed said that a PSU was OK even though its +12V
>> rail was at about 10.5V and kept the HD from spinning.
>> It's better to buy a cheap digital multimeter

> Yeah I second that. A cheap tester can be $9 on sale at
> Radio Shack, and blows the doors off a single-purpose
> tester. Even a nice meter can be had for $40, or you can
> blow a week's salary on a Fluke if you like.

I have a Fluke 73 that someone gave me in lieu of cash, and even
though it was their cheapest model it's built noticeably better than
my no-name, which has a 250V fuse for a 600V circuit (Fluke has a
jumbo 600V fuse wrapped in fiberglass cloth to prevent fragments from
flying out in case it explodes), and it's supposed to be able to run
2,000 hours on a single 9V battery, compared to just 250 hours for my
no-name.

> Having R, V, and I testing is nice, although I like capacitance
> testing too.

Also some meters, even inexpensive ones, now have an RS-232 serial
port and software to allow their readings to be monitored by a PC,
which can be useful for checking intermittent equipment. My no-name
has a feature that can do this by remembering the high and low values.

> Now my question is, does the single-purpose tester put the
> voltage source under load? It's possible for a supply to
> do well under no load, and drop miserably under load. No
> supply on the planet is an ideal voltage source.

The tester I borrowed has a pair of 5W load resistors for the +3.3V
and +5.0V.
5V through 5 ohms = 5W, and I learned the hard way that when a
resistor is run at its full power rating, it can melt plastic and burn
skin. Apparently, some other PSU testers are built the same way.
August 3, 2004 7:25:42 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

LadyTech wrote:

> I have to agree. I have a PSU tester and it tested a PSU as okay, but
> the PSU was faulty... I learned to use my digital multimeter from now
> on :-)

Based on the anecdotal evidence, I'd guess that some testers are only
checking for any voltage on a specified "pin," rather than precisely
measuring it, else a false positive with 1.5 V undervoltage would be
unlikely. If the tester is like $10 to $15 I can understand that, any
more and it should do precise testing, given that a $9 DMM can do the same.

michael
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:43:37 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On 2 Aug 2004 03:56:42 -0700, larrymoencurly@my-deja.com
(larrymoencurly) put finger to keyboard and composed:

>I have a couple of mobos made in 1997 that don't use the -5V or -12V,

I doubt it. The -12V rail would be needed for RS232.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
August 3, 2004 9:43:38 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Franc Zabkar wrote:

> On 2 Aug 2004 03:56:42 -0700, larrymoencurly@my-deja.com
> (larrymoencurly) put finger to keyboard and composed:
>
>
>>I have a couple of mobos made in 1997 that don't use the -5V or -12V,
>
>
> I doubt it. The -12V rail would be needed for RS232.

In my audio tinkering, I often used LM series regulators to lower the
voltage from my PS. A lot of electronics does this in one form or
another, as one size usually doesn't fit all. There are single-chip
inversion solutions as well, although it's probably easier to start with
a decent negative rail than generate one after the fact.

michael
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:43:38 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Tue, 03 Aug 2004 05:43:37 +1000, Franc Zabkar
<fzabkar@optussnet.com.au> wrote:

>On 2 Aug 2004 03:56:42 -0700, larrymoencurly@my-deja.com
>(larrymoencurly) put finger to keyboard and composed:
>
>>I have a couple of mobos made in 1997 that don't use the -5V or -12V,
>
>I doubt it. The -12V rail would be needed for RS232.
>
>
>- Franc Zabkar

What year would you consider to be the *average* transition point
towards serial drivers not needing -12V? I do think the typical
chips from National and TI still did at beginning of '97, but
don't know after that.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:43:38 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Franc Zabkar <fzabkar@optussnet.com.au> wrote in message news:<4d2tg0d4v9bqcs7u36j8qhaue0a0f09liu@4ax.com>...
> On 2 Aug 2004 03:56:42 -0700, larrymoencurly@my-deja.com
> (larrymoencurly) put finger to keyboard and composed:
>
>> I have a couple of mobos made in 1997 that don't use the -5V or
-12V,
>
> I doubt it. The -12V rail would be needed for RS232.

One is a 430TX mobo made by some defunct company and doesn't seem to
have any documentation available for it on the web. The other is an
FIC PA-2007 (VIA VP2 chipset) that uses a 5V-only Analog Devices brand
chip to convert between RS-232 and TTL levels and contains its own
charge pump circuitry to generate +10V and -10V for the RS-232 side.
When I bought this mobo used, its RS-232 ports didn't work except at
slow speeds because two .1 uF surface mount capacitors for the charge
pump were missing. I thought they'd been knocked off during
installation of a PCI card, but apparently they had vaporized when the
previous owner plugged or unplugged a parallel printer or serial
device with the power on. I know that the parallel port could do this
because my friend later unplugged a printer from this mobo and caused
the same capacitors to explode.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:43:39 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Guys,

Thank you so much for your input. These newsgroups never cease to amaze me
with their knowledge base.

RF
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 4:27:37 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Tue, 03 Aug 2004 03:25:42 GMT, Michael <none@none.com> wrote:

>LadyTech wrote:
>
>> I have to agree. I have a PSU tester and it tested a PSU as okay, but
>> the PSU was faulty... I learned to use my digital multimeter from now
>> on :-)
>
>Based on the anecdotal evidence, I'd guess that some testers are only
>checking for any voltage on a specified "pin," rather than precisely
>measuring it, else a false positive with 1.5 V undervoltage would be
>unlikely. If the tester is like $10 to $15 I can understand that, any
>more and it should do precise testing, given that a $9 DMM can do the same.
>
>michael


I keep both in my toolbox. I find the tester is most times right, and
is good for a quick-and-dirty check of things. If I have to get into
it more deeply, I haul out the dmm and crank it up.

I got the PS tester at CompUSA and it's come in very handy.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:01:05 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On 3 Aug 2004 01:42:47 -0700, larrymoencurly@my-deja.com (larrymoencurly) wrote:

> Even a nice meter can be had for $40, or you can
>> blow a week's salary on a Fluke if you like.

You could do a lot worse than this example:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=...


Chris Pollard

--
CG Internet café, Tagum City, Philippines
http://www.cginternet.net
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:01:06 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Christopher Pollard wrote:
> On 3 Aug 2004 01:42:47 -0700, larrymoencurly@my-deja.com (larrymoencurly) wrote:
>
>
>> Even a nice meter can be had for $40, or you can
>>
>>>blow a week's salary on a Fluke if you like.
>
>
> You could do a lot worse than this example:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=...
>
>
> Chris Pollard
>
Chinese copy, $3.99 on sale:

http://www.harborfreight.com
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:01:06 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Christopher Pollard" <rubbish@cginternet.net> wrote in message
news:m0lug0li1mfgf83vli99pmo52bmig1l41o@4ax.com...
> On 3 Aug 2004 01:42:47 -0700, larrymoencurly@my-deja.com (larrymoencurly)
wrote:
>
> > Even a nice meter can be had for $40, or you can
> >> blow a week's salary on a Fluke if you like.
>
> You could do a lot worse than this example:
>
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=...
>
>
> Chris Pollard
>
It's here new for $9.99.

http://www.baylornet.com/research/Simpson.260.Series.Mu...

AG
Anonymous
a b B Homebuilt system
a b ) Power supply
August 3, 2004 9:01:07 PM

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

On Tue, 03 Aug 2004 16:27:10 GMT, patrick <uce@ftc.gov> wrote:

>Christopher Pollard wrote:
>> On 3 Aug 2004 01:42:47 -0700, larrymoencurly@my-deja.com (larrymoencurly) wrote:
>>
>>
>>> Even a nice meter can be had for $40, or you can
>>>
>>>>blow a week's salary on a Fluke if you like.
>>
>>
>> You could do a lot worse than this example:
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=...
>>
>>
>> Chris Pollard
>>
>Chinese copy, $3.99 on sale:
>
>http://www.harborfreight.com

Where? I didn't see that offer. Could you please post the entire URL?

Thanks
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 12:36:29 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

"Micah Torrance" <Micah_torrance@therifleman.com> wrote in message
news:63fvg014d9aglejuosrb2b4o5cnn7d59ao@4ax.com...
> On Tue, 03 Aug 2004 03:25:42 GMT, Michael <none@none.com> wrote:
>
> >LadyTech wrote:
> >
> >> I have to agree. I have a PSU tester and it tested a PSU as okay,
but
> >> the PSU was faulty... I learned to use my digital multimeter from
now
> >> on :-)
> >
> >Based on the anecdotal evidence, I'd guess that some testers are
only
> >checking for any voltage on a specified "pin," rather than
precisely
> >measuring it, else a false positive with 1.5 V undervoltage would
be
> >unlikely. If the tester is like $10 to $15 I can understand that,
any
> >more and it should do precise testing, given that a $9 DMM can do
the same.
> >
> >michael
>
>
> I keep both in my toolbox. I find the tester is most times right,
and
> is good for a quick-and-dirty check of things. If I have to get into
> it more deeply, I haul out the dmm and crank it up.
>
> I got the PS tester at CompUSA and it's come in very handy.
>
>

I got mine at CompUSA as well :-).... Is it a CompUSA brand?
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 2:51:30 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Tue, 3 Aug 2004 20:36:29 -0400, "LadyTech"
<justme@invalid.fake.com> wrote:

>>
>> I got the PS tester at CompUSA and it's come in very handy.
>>
>>
>
>I got mine at CompUSA as well :-).... Is it a CompUSA brand?
>


Don't have it in front of me right now, but I believe it is.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 10:35:45 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On 3 Aug 2004 01:13:01 -0700, larrymoencurly@my-deja.com
(larrymoencurly) put finger to keyboard and composed:

>Franc Zabkar <fzabkar@optussnet.com.au> wrote in message news:<4d2tg0d4v9bqcs7u36j8qhaue0a0f09liu@4ax.com>...
>> On 2 Aug 2004 03:56:42 -0700, larrymoencurly@my-deja.com
>> (larrymoencurly) put finger to keyboard and composed:
>>
>>> I have a couple of mobos made in 1997 that don't use the -5V or
>-12V,
>>
>> I doubt it. The -12V rail would be needed for RS232.
>
>One is a 430TX mobo made by some defunct company and doesn't seem to
>have any documentation available for it on the web. The other is an
>FIC PA-2007 (VIA VP2 chipset) that uses a 5V-only Analog Devices brand
>chip to convert between RS-232 and TTL levels and contains its own
>charge pump circuitry to generate +10V and -10V for the RS-232 side.

You're right, of course. I have a FIC PA-2012 that uses the same (?)
chip, an ADM213EARS.

Here is the datasheet:
http://www.analog.com/UploadedFiles/Data_Sheets/3854509...

I've been aware of such 5V-only chips for quite some time (Maxim also
makes them), but until I saw the Analog Devices datasheet I was
struggling to explain why a designer would opt for 8 charge pump caps
and a more expensive IC instead of simply taking advantage of the
+/-12V supply rails. It appears that this IC is powered from the 5VSB
rail and has a low power shutdown mode in which two receivers remain
active for wake-on-interrupt monitoring.

In any case, your original statement that the motherboard doesn't
"use" these negative rails can be seen to be ambiguous. A PCI-only
board would not need the -5V rail since the PCI spec makes no
provision for same. However, the -12V supply *is* bussed to the PCI
slots, so the motherboard does actually use it.

>When I bought this mobo used, its RS-232 ports didn't work except at
>slow speeds because two .1 uF surface mount capacitors for the charge
>pump were missing. I thought they'd been knocked off during
>installation of a PCI card, but apparently they had vaporized when the
>previous owner plugged or unplugged a parallel printer or serial
>device with the power on. I know that the parallel port could do this
>because my friend later unplugged a printer from this mobo and caused
>the same capacitors to explode.

This is bizarre. I can't understand how the charge pump caps for the
RS232 driver IC can be affected by a failure of the parallel port. On
the PA-2012 board the parallel port is connected to a Winbond W83877F
multi-IO chip. I would think that your PA-2007 would be similar. In
any case, for a capacitor to vaporise, I would think that it would
have to experience a large overvoltage. I can't imagine that an
inductive spike from a data cable disconnection would have sufficient
energy to cause this failure (?). If anything, I would expect the I/O
chips to fail well before any passive component. Having said that, I
*have* seen failures in open collector drivers (eg 7406) in 20mA
current loop implementations of RS232 when the data cable has been
disconnected with power applied.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 10:35:46 AM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Wed, 04 Aug 2004 06:35:45 +1000, Franc Zabkar
<fzabkar@optussnet.com.au> wrote:

<snip>

>In any case, your original statement that the motherboard doesn't
>"use" these negative rails can be seen to be ambiguous. A PCI-only
>board would not need the -5V rail since the PCI spec makes no
>provision for same. However, the -12V supply *is* bussed to the PCI
>slots, so the motherboard does actually use it.

The motherboard may route -12V to PCI but what uses it?
Old soundcards with integral amp come to mind but nothing else.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 5:03:13 PM

Archived from groups: alt.comp.hardware.pc-homebuilt (More info?)

On Tue, 03 Aug 2004 16:27:10 GMT, patrick <uce@ftc.gov> wrote:

>Christopher Pollard wrote:
>> On 3 Aug 2004 01:42:47 -0700, larrymoencurly@my-deja.com (larrymoencurly) wrote:
>>
>>
>>> Even a nice meter can be had for $40, or you can
>>>
>>>>blow a week's salary on a Fluke if you like.
>>
>>
>> You could do a lot worse than this example:
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=...
>>
>>
>> Chris Pollard
>>
>Chinese copy, $3.99 on sale:
>
>http://www.harborfreight.com

Can anyone suggest a decent quality Digital Multimeter that's suitable
for testing PC measurements and sells online for a reasonable price. I
was looking at Ebay and the Fluke 77-III meter seemed to go for around
$60 and up. I can't recall where I saw that meter recommended, but one
of the big hardware test sites like Tom's Hardware, Anatech etc said
they used that model. I don't know much of anything about electricity
so I probably wouldn't ever use advanced features. I could see
measuring power supply voltages etc. Perhaps there is some good meters
between Fluke prices and ones that probably aren't all that accurate.

Thanks
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 6:17:29 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

On Tue, 03 Aug 2004 22:16:38 GMT, kony <spam@spam.com> put finger to
keyboard and composed:

>On Wed, 04 Aug 2004 06:35:45 +1000, Franc Zabkar
><fzabkar@optussnet.com.au> wrote:
>
><snip>
>
>>In any case, your original statement that the motherboard doesn't
>>"use" these negative rails can be seen to be ambiguous. A PCI-only
>>board would not need the -5V rail since the PCI spec makes no
>>provision for same. However, the -12V supply *is* bussed to the PCI
>>slots, so the motherboard does actually use it.
>
>The motherboard may route -12V to PCI but what uses it?
>Old soundcards with integral amp come to mind but nothing else.

Data acquisition cards.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
Anonymous
a b B Homebuilt system
a b ) Power supply
August 4, 2004 11:24:06 PM

Archived from groups: alt.certification.a-plus,alt.comp.hardware,alt.comp.hardware.homebuilt,alt.comp.hardware.pc-homebuilt (More info?)

Micah Torrance wrote:

> On Tue, 3 Aug 2004 20:36:29 -0400, "LadyTech"
> <justme@invalid.fake.com> wrote:
>
>
>>>I got the PS tester at CompUSA and it's come in very handy.
>>>
>>>
>>
>>I got mine at CompUSA as well :-).... Is it a CompUSA brand?
>>
>
>
>
> Don't have it in front of me right now, but I believe it is.

Mine is the CompUSA brand... Not too bad for a store brand :-)
!