David W. Hodgins wrote:
> On Sat, 26 Sep 2009 22:30:16 -0400, Paul <nospam@needed.com> wrote:
>
>> Can you give enough info, so we can see a picture of the label on the
>
> I had another look at the system today.
>
> I can't read the brand. It looks like MIOS, in a large script, that's
> mostly covered by the edge of the case. The info on the label is ...
>
> MIOS switching power supply
> Model No. KY-500ATX
> AC INPUT 115/230V~7A/4A,50-60Hz
> OUTPUT:500W
> +3.3V +5V +12V +5VSB
> 30.0A 32.0A 0.5A 2.0A
>
> Strange that it says on the label it's 500W, but all of the KY-500ATX
> models I find on google say that model number is a 400W power supply.
>
> With three usb devices connected, turning the machine on causes it
> to cycle through the post up to the point where it should be checking
> the ram, and then it reboots.
>
> Removing any one of the three devices allows it to boot.
>
> I measured the voltages on wires going to an unused power connector
> both with the three usb devices connected, and without any usb devices.
>
> Colour WithUsb WithoutUsb
> Yellow 12.11 12.2
> Red 5.21 5.2
> Orange 3.40 3.40
>
> Any suggestions appreciated.
>
> Thanks, Dave Hodgins
>
I can find one other report for the MIOS KY-500ATX.
His computer restarts as well. Video card 9600 GT.
The one interesting rail you missed in your readings, is the voltage on +5VSB.
If +5VSB drops, the system should stop. USB may be powered from that rail,
as your motherboard is pretty new.
The article archived in Toms (Google won't give it to me),
says the MIOS is rated 12V @ 24 amps.
Q9550 = 95W, 8.8 amps at 90% Vcore efficiency at max, from +12V.
Hard drive 0.6 amps at idle (times x 3)
Fans 0.5 amps
Video, say 5 amps max, 2 amps in the BIOS
CDROM 1.5 amps (zero, if no media in the tray)
Even if they all maxed, you're still short of 24 amps
by a good margin.
The processor won't run at max power at startup.
In the events you've listed, I'm guessing there isn't
a CDROM in the tray. That leaves a lot less than 24 amps
of total load. The video card won't go to 5 amps, unless
you're in a 3D game.
Since I can find at least three different brands using
the KY-500ATX model number, I'd have to conclude it
is an "OEM wonder", where they'll write virtually anything
they feel like on the label.
I'm not sure a multimeter is going to be enough to
catch the thing screwing up. You could include +5VSB in
your measurements, but if +5VSB dropped out, the system
would shut down. It likely wouldn't restart. So the symptoms
don't match. That leave the +12V being a load of ********,
and not an honest rating.
I think I'd just replace it. I;m not sure what else you
can do at this point. It is always good to have a
spare around anyway, so buy something nice that you
can reuse in a new build later.
If you want, you could try removing enough hardware
to get a good boot going, then run memtest/Prime95 or
whatever other stability checks you want. (Disconnect
the hard drives, boot from a LiveCD.) If the computer
passes those, and yet won't when extra load is added to
the supply, then your testing is done (and your PSU
goes in the trash). That would prove the other key
components in the system are working well.
Prime95 is available for Linux and Windows, and supports
loading all cores of a multicore processor. I like to see
a four hour run with no errors detected. Other people like
a slightly longer run.
So considering that the CPU probably draws another 5-10 amps and the
PSU is rated for just 18A @ +12V, you're probably right that it's too
weak for your system. But I have doubts this particular model PSU can
continuously put out 18A @ 12V or 500W, especially in a computer case
running at 30-40 Celcius (common) because the UL number, E210743, says
it's made by Sun Pro, which isn't exactly in high regard. I couldn't
find a review of any Sun Pro PSU, but if your PSU resembles this one
internally:
then it's not really a 500W unit but more like a 300W one.
Stick with PSUs manufactured by good companies, like Zippy-Emacs,
Enhance, Etasis, Lite-On, Delta, Fortron-Source, or Seasonic. The
last companies supply Antec, while OCZ uses Seasonic, and Corsair uses
Fortron-Source. JonnyGuru.com, HardOCP.com, HardwareSecrets.com, and
XbitLabs.com are some websites that do thorough reviews of PSUs.
On Mon, 28 Sep 2009 20:16:09 -0400, "David W. Hodgins"
<dwhodgins@nomail.afraid.org> wrote:
>On Sat, 26 Sep 2009 22:30:16 -0400, Paul <nospam@needed.com> wrote:
>
>> Can you give enough info, so we can see a picture of the label on the
>
>I had another look at the system today.
>
>I can't read the brand. It looks like MIOS, in a large script, that's
>mostly covered by the edge of the case. The info on the label is ...
>
>MIOS switching power supply
>Model No. KY-500ATX
>AC INPUT 115/230V~7A/4A,50-60Hz
>OUTPUT:500W
>+3.3V +5V +12V +5VSB
>30.0A 32.0A 0.5A 2.0A
>
>Strange that it says on the label it's 500W, but all of the KY-500ATX
>models I find on google say that model number is a 400W power supply.
Seems to be a generic PSU, doubtful it's worth even 400W and
should be considered the primary suspect. If you were to
open it, take a high-res picture and post that somewhere
like http://www.imageshack.us , someone might recognize who
made it, what it really is.
On Tue, 29 Sep 2009 14:48:13 -0400, kony <spam@spam.com> wrote:
> should be considered the primary suspect. If you were to
> open it, take a high-res picture and post that somewhere
> like http://www.imageshack.us , someone might recognize who
> made it, what it really is.
I've taken the system back to the shop that I purchased it from,
last month. They're in the process of replacing the power supply
with one that has a higher +12v amperage.
The tech I talked to, understood the problem, but was surprised by
it, as they haven't seen the problem with the same power supply and
video card, on other systems they've built, but those systems didn't
have a quad core, 4GB of ddr3 ram, with two 1.5TB 7200rpm sata
drives.
The combination of hardware in this system was just enough to
overtax the power supply, although it could run for a couple of days
and appear to be ok, but would then spontaneously reboot.
Being able to consistently have the system fail to boot, simply by
adding more usb devices, was enough to prove to their satisfaction,
that the power supply was not adequate.
I hate intermittent problems like this, as it's difficult to know
whether or not you've fixed the problem, until the system has been
running for quite a while.
Regards, Dave Hodgins
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On Tue, 29 Sep 2009 17:16:13 -0400, "David W. Hodgins"
<dwhodgins@nomail.afraid.org> wrote:
>On Tue, 29 Sep 2009 14:48:13 -0400, kony <spam@spam.com> wrote:
>
>
>> should be considered the primary suspect. If you were to
>> open it, take a high-res picture and post that somewhere
>> like http://www.imageshack.us , someone might recognize who
>> made it, what it really is.
>
>I've taken the system back to the shop that I purchased it from,
>last month. They're in the process of replacing the power supply
>with one that has a higher +12v amperage.
>
>The tech I talked to, understood the problem, but was surprised by
>it, as they haven't seen the problem with the same power supply and
>video card, on other systems they've built, but those systems didn't
>have a quad core, 4GB of ddr3 ram, with two 1.5TB 7200rpm sata
>drives.
Maybe, but if they are using bottom-end generic PSU do you
reasonably expect them to concede it's junk?
At this point I would not trust them much. "IF" it is the
grade of PSU I suspect it is, regardless of it's actual
output current capability it could be a poor choice for any
system, even a low-end all integrated one since a PSU should
reasonably be expected to last the life of the system, not
just for a few months of stability.
I've just seen it too many times before, shops buy the
cheapest thing with a good looking label and hope it
outlasts their warranty.
>
>The combination of hardware in this system was just enough to
>overtax the power supply, although it could run for a couple of days
>and appear to be ok, but would then spontaneously reboot.
.... but that is now, far too many times such PSU fail within
24 months. Wecome to the PSU lottery, where marketing
departments prevail over legal or engineering specs.
>
>Being able to consistently have the system fail to boot, simply by
>adding more usb devices, was enough to prove to their satisfaction,
>that the power supply was not adequate.
>
>I hate intermittent problems like this, as it's difficult to know
>whether or not you've fixed the problem, until the system has been
>running for quite a while.
>
>Regards, Dave Hodgins
Yep, personally I tear open a PSU the moment I get it,
warranty be ****ed, because I'd rather know it was junk than
spend the time for what might only be worth $20. It's a bit
like automobiles, at some point I just stopped trusting
anyone who had a financial incentive to cheap out on
something.
On Tue, 29 Sep 2009 20:24:45 -0400, kony <spam@spam.com> wrote:
> Maybe, but if they are using bottom-end generic PSU do you
> reasonably expect them to concede it's junk?
Just a followup, to confirm replacing the power supply fixed the
problem of spontaneous reboots, and occasional Xorg lockups,
on a system with a nvidia geforce 9600gt video card, 4gb ddr3 ram,
quad core cpu, two 1.5TB 7200rpm sata drives, and an 80GB ide hard
drive.
I'd misread the label on the original power supply. It did have
24 amps on the +12v rail, but that wasn't enough for all of the
stuff I had in the system.
The power supply was replaced with a Thermaltake 650W supply,
with up to 52 amps on the +12v rail.
The system has been running steadily for about 2 weeks now. Yeah!
:-)
Regards, Dave Hodgins
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Re: Recommended power supply wattage. 
Linear Mode
